Small NodeJS script to recursively rename the extension of files inside a directory

renameExt.js

#!/usr/bin/env node

const { sync: globSync } = require('glob');
const { moveSync } = require('fs-extra');
const { exit } = require('process');

const dir = process.argv[2];
const oldExt = process.argv[3];
const newExt = process.argv[4];

if (!dir || !oldExt || !newExt) {
  console.log(`USAGE: renameExt [directory] [old extension] [new extension]`);
  exit(1);
}

const files = globSync(`${dir}/**/*.${oldExt}`);

for (const file of files) {
  const fileWithoutExtension = file.slice(0, file.indexOf(`.${oldExt}`));
  moveSync(file, `${fileWithoutExtension}.${newExt}`);
}