question/implement-promise-any

[giscus[bot]]

question/implement-promise-any

北美前端面试攻略

https://us-fe.github.io/question/implement-promise-any.html

[xiaoyu2er]

/**
 * @param {Array<Promise>} promises
 * @return {Promise}
 */
function any(promises) {
  // your code here
  return new Promise((resolve, reject) => {
    const errors = [];
    let len = promises.length;

    const throwError = () => {
      reject(new AggregateError(
        'No Promise in Promise.any was resolved',
        errors
      ))
    }

    if (len == 0) {
      throwError();
    }

    promises.forEach((p, i) => {
      Promise.resolve(p)
        .then(resolve)
        .catch((e) => {
          errors[i] = e;
          if (--len === 0) {
            throwError();
          }
        })
    })
  });
}