Promise.all with wait all.

promise-all-wait.js

errors = [];

var promises = [
    Promise.reject(new Error('Rejects immediately!')),
    new Promise((resolve) => setTimeout(resolve, 5000)).then(() => 'Resolved after 5 seconds!')
];

promises = promises.map((promise, i) => promise.catch(error => {
    errors[i] = error;
}));

Promise.all(promises)
.then(results => {
    errors.forEach((error, i) => {
        results[i] = error;
    });

    results.forEach(res => {
        console.log(res instanceof Error ? res.message : res);
    });
});

// Prints after 5 seconds:
// Rejects immediately!
// Resolved after 5 seconds!