Expands out JSON with dots in the property name.

undottify.js

/* Input:
  {
    "person.name.first": "Ryan",
    "person.name.last": "Haskell-Glatz",
    "person.age": 23
  }
  ... undottify magic ...
  Output:
  {
    "person": {
      "name": {
        "first": "Ryan",
        "last": "Haskell-Glatz"
      },
      "age": 24
    }
  }
*/
const undottify = (obj) =>
  Object.keys(obj).reduce((newObj, key) =>
    key.split('.').reduceRight((value, key, index, list) => ({
      ...list.slice(0, index).reduce((value, key) => value[key] || {}, newObj),
      [key]: value
    }), obj[key])
  , {})