"compose" function that handles both sync and async functions

compose.js

// Async compose
const compose = (…functions) => input => functions.reduceRight((chain, func) => chain.then(func), Promise.resolve(input));

// Functions fn1, fn2, fn3 can be standard synchronous functions or return a Promise
compose(fn3, fn2, fn1)(input).then(result => console.log(`Do with the ${result} as you please`))

This works great. 👍

Awesome, I'm glad it is useful to you too. 🤗

great, very useful
could add catch if it's necessary:
const compose = (…functions) => input => functions.reduceRight((chain, func) => chain.then(func), Promise.resolve(input)).catch(err => console.warn(err));

Great!