JavaScript

Exercises Set 11

// Write your code below this line

fetchFastest([fetchUserUS, fetchUserEU, fetchUserAsia])
  .then(console.log)
  .catch(console.error);

// Write your code below this line

const fetchUserUS = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (Math.random() < 0.2) {
        reject();
      } else {
        resolve("oliver");
      }
    }, 200);
  });
}

const fetchUserEU = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (Math.random() < 0.2) {
        reject();
      } else {
        resolve("oliver");
      }
    }, 300);
  });
}

const fetchUserAsia = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      if (Math.random() < 0.2) {
        reject();
      } else {
        resolve("oliver");
      }
    }, 150);
  });
}

const fetchFastest = fetchFunctions => {
  return new Promise((resolve, reject) => {
    let errors = 0;
    
    fetchFunctions.forEach((fetchFunction) => {
      fetchFunction()
        .then(message => resolve(message))
        .catch(() => {
          errors++;
          if (errors === fetchFunctions.length) {
            reject("All requests failed");
          }
        });
    });
  });
}

fetchFastest([fetchUserUS, fetchUserEU, fetchUserAsia])
  .then(console.log)
  .catch(console.error);