How to push new value to Store object?

Question

foodList : {
    'fruits' : ['apple', 'banana'],
    'hamburgers: ['bigmac', 'crispy']
}

In case of above data structure, How to add new kiwi to fruits in Redux?

case "FRUIT_ADD_SUCCESS" : 

    action.payload = 'kiwi';
    return { 
        ...state,

        // Cannot read property 'push' of undefined 
        foodList: state.foodList['fruits'].push(action.payload)

        // Disappear previous values 
        foodList: state.foodList['fruits'] = action.payload  
    }

How to push new value to Store object?

Answer 1

This should work:

case 'FRUIT_ADD_SUCCESS':
  action.payload = 'kiwi';

  const newFoodList = {
    ...state.foodList,
    fruits: [...state.foodList.fruits, action.payload],
  };

  return {
    ...state,
    newFoodList,
  };