0_promise_test.mjs

#!/bin/sh
':' //; exec "`command -v node`" "--experimental-modules" "--no-warnings" "$0" "$@"

import fsOrig from 'fs'; const fs = fsOrig.promises;
import path from 'path';


function delay(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

// "main loop" ... a promise closure to enable await.
(async () => {

  const sPath = process.cwd();
  
  console.log('processing ...');

  // async getting all filenames
  let files = await fs.readdir(sPath);
  
  // kick off all tasks async, and collect their promises
  let tasks = files.map( async file => {
    // filter `.` files (hidden)
    if (file[0] === '.') return;

    // reconstruct the full file path
    let fullPath = path.resolve(sPath, file);

    // artificial wait - mind: all tasks are in parallel, they end at the same time + a few nano secs (not after each other)
    // so the ending time is about 1300ms, not `files.length * 1300`
    await delay(1300);

    console.log(fullPath);
  });
  // wait for all tasks to finish
  await Promise.all(tasks);

  console.log('done.');

})().catch(console.error);

package.json

{
  "name": "promise_test",
  "version": "1.0.0",
  "bin": "0_promise_test.mjs"
}

README.md

usage

get the files

• git clone https://gist.github.com/BananaAcid/7ff43ecc26673da3fa64d94b80ab22a4 .
• npm i gist:7ff43ecc26673da3fa64d94b80ab22a4 && cd node_modules/promise_test/

run the file

• ./0_promise_test.mjs (has a shebang, you might want to chmod +x 0_promise_test.mjs to mark it as executable)
• node --experimental-modules 0_promise_test.mjs
• npm i esm && node -r esm 0_promise_test.mjs