Node - get the contents of all the files in DIR

node-get-file-contents.js

const fs = require('fs')
const path = require('path')

const DIR = 'input/';
const readFile = name => fs.readFileSync(name);

(async () => {

  const files = fs.readdirSync(DIR)
    .filter(s => s.match(/\.csv$/)) // only .csv files -- change to whatever you want.
    .map(name => path.join(DIR, name))
    .map(readFile)
    .map(buffer => buffer.toString());
    
  console.log(files);
});