CHALLENGE

const compose = (...fns) => fns.reduce((f, g) => (...args) => f(g(...args)));
const pipe = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));

const add1 = x => x + 1;
const double = x => x * 2;
const square = x => x * x;

const composed = compose(square, double, add1);
const piped = pipe(square, double, add1);

console.log(composed(3), piped(3));