实现 Promise.race

Promise.race() 方法返回一个 promise，一旦迭代器中的某个 promise 解决或拒绝，返回的 promise 就会解决或拒绝。

const t = new Promise((resolve, reject) => {
  setTimeout(() => {
    // resolve("success");
    reject("t");
  }, 1000);
});

const h = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve("success");
    // reject("h");
  }, 2000);
});

Promise.myRace = function (promises) {
  return new Promise((resolve, reject) => {
    if (!Array.isArray(promises)) return;
    const len = promises.length;
    for (let i = 0; i < len; i++) {
      Promise.resolve(promises[i])
        .then((r) => {
          resolve(r);
        })
        .catch((e) => {
          reject(e);
        });
    }
  });
};

Promise.myRace([t, h])
  .then((r) => {
    console.log(r, "r");
  })
  .catch((e) => {
    console.log(e, "e");
  });

//t e