Random object properties generator (example with 5.000 properties: keys with 21 chars, values with 6 chars)

randomObjectPropertiesGenerator.js

const obj = {};

for (let index = 0; index < 5000; index++) {
  obj[makeid(21)] = makeid(6);
}

function makeid(length) {
  let result = '';
  const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  const charactersLength = characters.length;
  for (let i = 0; i < length; i++) {
    result += characters.charAt(Math.floor(Math.random() * charactersLength));
  }
  return result;
}

copy(obj);