deepclone.js

function clone(data) {           
  if (Array.isArray(data)) {     
    return data.map(clone)       
  } else if (data.constructor === Object) {
    return Object.entries(data)
      .map(([key, value]) => ({[key]: clone(value)}))
      .reduce((obj, cur) => ({...obj, ...cur}))
  }
  return data
}

function clone2(src) {
  const dest = Array.isArray(src) ? [] : {}

  for (let key in src) {
    const value = src[key]
    dest[key] = typeof value === "object" ? copy(value) : value
  }
  
  return dest
}