const { readFile } = require('fs/promises')
const writeJsonFile = require('write-json-file')

function wait(ms) {
  return new Promise(resolve => setTimeout(resolve, ms))
}

async function run() {
  await wait(100)

  const data = JSON.parse((await readFile('bar.json')).toString())

  await writeJsonFile('foo.json', data)
}

async function main() {
  while (true) {
    await run()
  }
}

main()