.js

/* test qs parse and stringify, running in https://npm.runkit.com/qs */

const qs = require('qs');
const assert = require('assert');

const obj= {
  Data: {
    [0]: {
      title: 'As',
      slug: 'asas',
      companies: ['123']
    }
  }
};
const resultStringify = qs.stringify(obj);
const resultObj = qs.parse(resultStringify);
assert.deepEqual(obj, resultObj);

const strPost = 'Data[0][title]=asas asdasd&Data[0][content]=asda&Data[0][companies][0]=123&Data[0][companies][1]=4565';
const resultParse = qs.parse(strPost);
console.log("Success!", resultStringify, resultObj, resultParse);