Generate a quick and dirty type "blueprint" of a JS object/array/variable

toBlueprint.js

function toBlueprint(obj) {
  if (!obj || typeof obj !== 'object') {
    return obj;
  }
  if(Array.isArray(obj)) {
    return obj.map(toBlueprint) // nit: won't unify common props
  }
  return Object.keys(obj).reduce((acc, key) => {
    let blueprint = typeof obj[key];
    if (blueprint === "object" && blueprint) {
      blueprint = toBlueprint(obj[key])
    }
    acc[key] = blueprint;
    return acc;
  }, 
  {})
}