Quick Node Script to flatten JSON

flatten.js

// https://stackoverflow.com/questions/19098797/fastest-way-to-flatten-un-flatten-nested-json-objects
function flatten(data) {
  const result = {}

  function recurse(cur, prop) {
    if (Object(cur) !== cur) {
      result[prop] = cur
    } else if (Array.isArray(cur)) {
      for (let i = 0, l = cur.length; i < l; i++)
        recurse(cur[i], prop + '[' + i + ']')
      if (l === 0)
        result[prop] = []
    } else {
      let isEmpty = true
      for (let p in cur) {
        isEmpty = false
        recurse(cur[p], prop ? prop + '.' + p : p)
      }
      if (isEmpty && prop)
        result[prop] = {}
    }
  }

  recurse(data, '')
  return result
}

const fs = require('fs')

const tw = String(fs.readFileSync('./target.json'))

const twJsObj = JSON.parse(tw)

const twFlattenJson = JSON.stringify(flatten(twJsObj))

fs.writeFileSync('./flatten.json', twFlattenJson)