javascript - Cleaner/shorter way to update nested state in Redux?

Question

Sometimes reducers get kind of messy:

const initialState = {
    notificationBar: {
        open: false,
    },
};

export default function (state = initialState, action) {
  switch (action.type) {
    case actions.LAYOUT_NOTIFICATIONBAR_OPEN:
      return Object.assign({}, state, {
        // TODO: Find a cleaner way to do this!
        notificationBar: Object.assign({}, state.notificationBar, {
          open: true,
        }),
      });
    default:
      return state;
  }
}

Is there a more terse way to do this?

Answer 1

UPD: it's now a part of the ES2018

It might be slightly improved via a non-standardised yet properties spread syntax:

return {
    ...state,
    notificationBar: {
        ...state.notificationBar,
        open: true,
    },
};