Beautiful ES6

beautiful.js

const fs = require('fs');

const head = ([x, ...t]) => x;
const tail = ([x, ...t]) => t;

const compose = (f, ...rest) => (x) =>
  rest.length === 1 
  ? head(rest)(f(x))
  : compose(head(rest), ...tail(rest))(f(x));

const promiseCb = (resolve, reject) => (error, data) => error ? reject(error) : resolve(data);

const promisify = (fun) => (...args) => new Promise((res, rej) => fun(...args, promiseCb(res, rej)));

const readFile = promisify(fs.readFile);

const bufToString = (x, encoding) => x.toString(encoding);

const bufToUTF8 = (x) => bufToString(x, 'utf-8');

const splitString = (x, delim) => x.split(delim);

const splitStringNewLine = (x) => splitString(x, '\n')

const filterEmpty = (x) => x.filter((el) => el.length > 0);

readFile('./text.txt')
  .then(
    compose(
      bufToUTF8, 
      splitStringNewLine,
      filterEmpty,
      console.log))
  .catch(error => console.error(error.stack));