const fs = require('fs').promises // Returns a Promise<number> that computes the most recent // modification time for any file inside a directory async function modifiedTime(path) { // First, we wait for the fs.stat() Promise const stats = await fs.stat(path) const {mtimeMs} = stats // If this path is a file, return its modification time if (!stats.isDirectory()) return mtimeMs // If this is a directory, check all files inside for later modified times // Get a list of all files/subdirectories in the directory const files = await fs.readdir(path) // Then get the modified time of each file/subdirectory in parallel const modifiedTimes = await Promise.all(files.map(file => modifiedTime(path + '/' + file) )) // Return the latest modification time return Math.max(mtimeMs, ...modifiedTimes) } // Even though we return a number from modifiedTime, the number // is wrapped in a Promise because it is an async function modifiedTime('.').then(mTime => { console.log(`Most recent modification: ${new Date(mTime)}`) })