Script to rename files based on regex pattern in javascript

rename.js

const fs = require('fs'),
  path = require('path'),
  dir = '~/Downloads',
  match = /.*_(\w+\.part\d+.rar)/ // change this to whatever pattern needed

files = fs.readdirSync(dir)
files.filter(f => f.match(match)).forEach(f => {
  const fpath = path.join(dir, f),
      newfpath = path.join(dir, f.replace(match, (m, p1) => p1))
  fs.renameSync(fpath, newfpath)
})