langKeyDiff.js

const master = process.argv[2]
const source = process.argv[3]

const fs = require('fs')

if (master === undefined || source === undefined) {
  console.log('Insufficient arguments.')
  process.exit(1)
}

const masterObj = JSON.parse(fs.readFileSync(master, { encoding: 'utf8' }))
const sourceObj = JSON.parse(fs.readFileSync(source, { encoding: 'utf8' }))
const increasedKeyArray = {}
const decreasedKeyArray = {}

Object.keys(masterObj).forEach(key => {
  if (!(sourceObj[key] === undefined)) {
    masterObj[key] = sourceObj[key]
  } else {
    increasedKeyArray[key] = masterObj[key]
  }
})

Object.keys(sourceObj).forEach(key => {
  if (masterObj[key] === undefined) {
    decreasedKeyArray[key] = sourceObj[key]
  }
})

fs.writeFileSync('result.json', JSON.stringify(masterObj, null, 2))
fs.writeFileSync(
  'increasedKeys.json',
  JSON.stringify(increasedKeyArray, null, 2)
)
fs.writeFileSync(
  'decreasedKeys.json',
  JSON.stringify(decreasedKeyArray, null, 2)
)