Get first fulfilled promise

Question

If I have two promises A and B, only one of which will succeed, how can I get whichever one fulfills successfully? I\'m looking for something similar to Promise.race

Answer 1

ES2021 / ES12 - Promise.any

Promise.any - first fulfilled Promise wins.

const promiseA = Promise.reject();
const promiseB = new Promise((resolve) => setTimeout(resolve, 100, 'succeed'));

const promises = [promiseA, promiseB];


Promise.race(promises).then((value) => console.log(value)); // rejected promise

Promise.any(promises).then((value) => console.log(value)); // "succeed"

Notice that any is ignoring the first rejected promise - promiseA because promiseB is being resolved

If all of the given promises are rejected, then the returned promise is rejected.

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This is finished proposal and it's scheduled for ES2021 (expected to be released in June 2021)