Redux Reducer - how can I save this state as object? (I'm getting "Parsing Error")

My code looks like this:

import { SAVE_SEARCH } from '../actions/index';

export default function (state = [], action) {
  switch (action.type) {
    case SAVE_SEARCH:
      return [...state, action.payloadTwo, action.payloadOne];
    default:
      return state;
  }
}

And I'm getting such result in my state:

It works, but this is an array. I want to change it to object, like so:

    case SAVE_SEARCH:
      return [...state, { action.payloadTwo: action.payloadOne }];

So searchTerm would be the key in the object, and the data will be save as object key values.

But this code gives me an error:

I know it is obvious for you. Why I can't code it like this? Why I'm getting "Parsing Error"?

---------------

EDIT:

Many thanks to @marekful for his answer! Now it works!

My action.js code:

import axios from 'axios';

export const SAVE_SEARCH = 'SAVE_SEARCH';

export function searchTest(query) {
  const githubApi = `https://api.github.com/search/repositories?q=${query}&sort=stars&order=desc`;
  const request = axios.get(githubApi);
  return (dispatch) => {
    request.then(({ data: dataFromGithub }) => {
      dispatch({ type: SAVE_SEARCH, payloadOne: query, payloadTwo: dataFromGithub });
    });
  };
}

reducer code:

import { SAVE_SEARCH } from '../actions/index';

export default function (state = [], action) {
  switch (action.type) {
    case SAVE_SEARCH:
      const o = {};
      o[action.payloadOne] = action.payloadTwo;
      return [...state, o];
    default:
      return state;
  }
}

Result:

Solution

In object literals, keys can only be string literals (values can be object references): {"someKey": object.property}

You can, however, use object references or function return values as object keys using array notation (but it still has to be a string):

let o = {};
o[action.payloadTwo] = action.payloadOne;
return [...state, o];