pureObject.ts

export function pureObject(o: unknown) {
  if (!isObject(o)) return false

  const ctor = o.constructor
  if (ctor == null) return true

  const prot = ctor.prototype
  if (!isObject(prot)) return false

  if (!Object.prototype.hasOwnProperty.call(prot, 'isPrototypeOf')) return false

  return true
}

function isObject(o: unknown) {
  return Object.prototype.toString.call(o) === '[object Object]'
}