Promise.some

Promise.some(
    Iterable<any>|Promise<Iterable<any>> input,
    int count
) -> Promise

Given an Iterable(arrays are Iterable), or a promise of an Iterable, which produces promises (or a mix of promises and values), iterate over all the values in the Iterable into an array and return a promise that is fulfilled as soon as count promises are fulfilled in the array. The fulfillment value is an array with count values in the order they were fulfilled.

This example pings 4 nameservers, and logs the fastest 2 on console:

Promise.some([
    ping("ns1.example.com"),
    ping("ns2.example.com"),
    ping("ns3.example.com"),
    ping("ns4.example.com")
], 2).spread(function(first, second) {
    console.log(first, second);
});

If too many promises are rejected so that the promise can never become fulfilled, it will be immediately rejected with an AggregateError of the rejection reasons in the order they were thrown in.

You can get a reference to AggregateError from Promise.AggregateError.

Promise.some(...)
    .then(...)
    .then(...)
    .catch(Promise.AggregateError, function(err) {
        err.forEach(function(e) {
            console.error(e.stack);
        });
    });