.finally()

Returns a new Promise object after the previous Promise in the chain has been resolved or rejected. This last part of the chain will execute no matter what.

myPromiseObject.then(fulfilledPromiseCallback).finally(finalPromiseCallback);

.finally() can be used with or without .then() and/or .catch().

const myPromise = new Promise((resolve, reject) => {
  if (2 + 2 === 4) {
    resolve('Fulfilled');
  } else {
    reject('Rejected');
  }
});

myPromise
  .then((result) => {
    console.log(result);
  })
  .catch((err) => {
    console.log(`${err.status} - ${err.errorType}: ${err.message}`);
  })
  .finally(() => console.log('Operations have ended.'));
/*
  Output: 
  Fulfilled
  Operations have ended.
  */