promiseAny

/**
 * @param {Array} iterable
 * @return {Promise}
 */
export default function promiseAny(iterable) {
  return new Promise((resolve, reject) => {
    const errors = [];
    let rejectedCount = 0;
    let settled = false;

    if (iterable.length === 0) {
      resolve(new AggregateError([], 'All promises were rejected'));
      return;
    }

    iterable.forEach((promise, idx) => {
      Promise.resolve(promise).then(
        (value) => {
          if (settled) {
            return;
          }
          settled = true;
          resolve(value);
        },
        (error) => {
          errors[idx] = error;
          rejectedCount++;
          if (rejectedCount === iterable.length) {
            reject(new AggregateError(errors, 'All promises were rejected'));
          }
        }
      )
    })
  })
}

/**
const p0 = new Promise((resolve) => {
  setTimeout(() => {
    reject(42);
  }, 400);
});
const p1 = new Promise((resolve, reject) => {
  setTimeout(() => {
    reject('Err!');
  }, 100);
});

try {
  await promiseAny([p0, p1]);
} catch (err) {
  console.log(e instanceof AggregateError); // true
  console.log(e.errors); // [ 42, "Err!" ]
}
*/