Get directory size (used in stackblitz as a replacement of `du -sh` command)

dirsize.js

import { join } from 'path';
import { readdir, stat } from 'fs/promises';

function humanFileSize(bytes, si = false, dp = 1) {
  const thresh = si ? 1000 : 1024;

  if (Math.abs(bytes) < thresh) {
    return bytes + ' B';
  }

  const units = si
    ? ['kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']
    : ['KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB'];
  let u = -1;
  const r = 10 ** dp;

  do {
    bytes /= thresh;
    ++u;
  } while (
    Math.round(Math.abs(bytes) * r) / r >= thresh &&
    u < units.length - 1
  );

  return bytes.toFixed(dp) + ' ' + units[u];
}

const dirSize = async (dir) => {
  const files = await readdir(dir, { withFileTypes: true });

  const paths = files.map(async (file) => {
    const path = join(dir, file.name);

    if (file.isDirectory()) return await dirSize(path);

    if (file.isFile()) {
      const { size } = await stat(path);

      return size;
    }

    return 0;
  });

  return (await Promise.all(paths))
    .flat(Infinity)
    .reduce((i, size) => i + size, 0);
};

(async () => {
  const size = await dirSize(process.argv[2] ? process.argv[2] : '.');
  console.log(humanFileSize(size));
})();