size of js object

gistfile1.txt

const getSizeOfObject = obj => {
  const typeSizes = {
    "undefined": () => 0,
    "boolean": () => 4,
    "number": () => 8,
    "string": item => 2 * item.length,
    "object": item => !item ? 0 : Object
      .keys(item)
      .reduce((total, key) => sizeOf(key) + sizeOf(item[key]) + total, 0)
  };

  const sizeOf = value => typeSizes[typeof value](value);

  const formatByteSize = bytes => {
    if(bytes < 1024) return bytes + " bytes";
    if(bytes < 1048576) return (bytes / 1024).toFixed(3) + " KiB";
    if(bytes < 1073741824) return (bytes / 1048576).toFixed(3) + " MiB";
    return (bytes / 1073741824).toFixed(3) + " GiB";
  };
  
  return formatByteSize(sizeOf(obj));
}