my-ls.js

#!/usr/bin/env node 

const fs = require("node:fs");
const path = require("node:path");

function parseArgs(args) {
  let showAll = false;
  let targetDir = ".";

  for (const arg of args) {
    if (arg === "-a") {
      showAll = true;
    } else if (!arg.startsWith("-")) {
      targetDir = arg;
    }
  }

  return { showAll, targetDir };
}

function listDirectory(dirPath, showAll) {
  let files = fs.readdirSync(dirPath);

  if (!showAll) {
    files = files.filter(file => !file.startsWith("."));
  }

  return files.sort();
}

function main() {
  const args = process.argv.slice(2);
  const { showAll, targetDir } = parseArgs(args);

  const files = listDirectory(targetDir, showAll);
  console.log(files.join("\n"));
}

main();