Pulumi Interview

index.js

const oldData = {
  "region": "us-west-1",
  "sku": {
    "tier": "standard",
    "name": "s1a",
  },
  "replication": "local",
  "oldKey": "oldVal"
}

const newData = {
  "region": "us-west-1",
  "sku": {
    "tier": "standard",
    "name": "s2a",
  },
  "replication": "global",
  "newKey": "newVal"
}

function getPrefix (prefix, key) {
  if (prefix === '') {
    return key
  }

  return `${prefix}.${key}`
}

function diff(oldData, newData, prefix = '') {
  const diffs = []

  for (key in newData) {
    if (oldData.hasOwnProperty(key)) {
      if(typeof oldData[key] === 'object' && typeof newData[key] === 'object') {
        diffs.push(...diff(oldData[key], newData[key], getPrefix(prefix, key) ))

      }
      else if (oldData[key] !== newData[key]) {
        diffs.push(`${getPrefix(prefix, key)}: ${oldData[key]} -> ${newData[key]}`)
      }
    } else {
      diffs.push(`${getPrefix(prefix, key)}: +${newData[key]}`)
    }
  }

  for (key in oldData) {
    if (!newData.hasOwnProperty(key)) {
      diffs.push(`${getPrefix(prefix, key)}: -${oldData[key]}`)
    }
  }

  return diffs
}

console.log(diff(oldData, newData))