.then() can be used as a .finally() if chained after a .catch()

finally.js

new Promise((resolve, reject) => setTimeout(() => resolve('yay'), 100))
    .then(val => console.log(val)) // yay
    .catch(err => console.error(err)) // (never hit)
    .then(() => console.log('finally 1'));

new Promise((resolve, reject) => setTimeout(() => reject('nay'), 200))
    .then(val => console.log(val)) // (never hit)
    .catch(err => console.error(err)) // nay
    .then(() => console.log('finally 2'));

/* 
Output:
> yay
> finally 1
> nay
> finally 2
*/