Merge array with nested objects if id matches or add to the end

Question

I am trying to assign clone/merge object, that has array where id matches or add to an end:

  newState = Object.assign({}, state, {
    data: {
      newest: {
        result: action.payload.result,
        list: action.payload.items,
        request: action.payload.items
      },
      itemList: [
        ...state.data.itemList,
        {
           id: action.payload.id,
           list: action.payload.items,
           request: action.payload.items
        }
      ]
    }
  });

In this case ...state.data.itemList is an array with objects where I want to find an existing object with ID and merge list + request nested objects. However, if there is no object with that ID I want to add it to the list.

Current approach always adds it to the end, which of course is not what I want.

Thanks.

Answer 1

Don't feel pressured into making the new state in one operation. Here would be my implementation. I would check my array for the current id using Array#some . Here are some fun ES6 tricks too.

const newState = {...state}
const {result, items, id, items} = action.payload
const data = {newest: {result, list: items, request: items}}
const hasId = newState.data.itemList.some(item => item.id === id)
if (!hasId) {
  newState.data.itemList.push({id, list: items, request: items})
}
return {...newState, data}