const {parse, stringify} = require('comment-json')

const parsed = parse(
  `{"foo": 9007199254740993}`,
  // The reviver function now has a 3rd param that contains the string source.
  (key, value, {source}) =>
    /^[0-9]+$/.test(source) ? BigInt(source) : value
)

console.log(parsed)
// {
//   "foo": 9007199254740993n
// }

stringify(parsed, (key, val) =>
  typeof value === 'bigint'
    // Pay attention that
    //   JSON.rawJSON is supported in node >= 21
    ? JSON.rawJSON(String(val))
    : value
)
// {"foo":9007199254740993}