grantcarthew/node-scalable-blob-store

const path = require('path');
const fsp = require('fs').promises;

module.exports = fsBlobDirLatest;

/**
 *  Returns the most recently created directory from within the fsPath.
 *  Returns false if the fsPath does not exist or has no directories within it.
 *
 *  @param {String} fsPath
 *  @returns {Promise<String|Boolean>}
 */
async function fsBlobDirLatest(fsPath) {
  const listOfDir = [];
  try {
    const fsItems = await fsp.readdir(fsPath);

    for (const fsItem of fsItems) {
      const fsItemPath = path.join(fsPath, fsItem);
      const fsItemStat = await fsp.stat(fsItemPath);
      fsItemStat.isDirectory() &&
        listOfDir.push({
          fsItem,
          fsItemStat,
        });
    }
  } catch (err) {
    if (err.code === 'ENOENT') {
      return false;
    }
    throw err;
  }

  if (listOfDir.length < 1) {
    return false;
  }

  if (listOfDir.length > 1) {
    listOfDir.sort((a, b) => {
      if (a.fsItemStat.birthtimeMs === b.fsItemStat.birthtimeMs) {
        return a.fsItem > b.fsItem ? 1 : -1;
      }
      return b.fsItemStat.birthtimeMs - a.fsItemStat.birthtimeMs;
    });
  }

  return listOfDir[0].fsItem;
}