How to repeat the same Promise in NodeJS with an Array input until it resolves or the Array ends?-CodePudding

I have an array of URLs for the same audio file which are not always working due to server loads. So, whenever a URL is needed, I should check first the headers of the first URL to make sure it's working now. If it's not working, I check the next URL.. and so on until the array ends.

My question is: How to chain a recurring of the same Promise (different URL each time) with the ability to break the chain once a working URL is found?

CodePudding user response：

While a recursive Promise-returning function would be simple enough...

const getWorkingAudio = (i = 0) => {
  if (i === urls.length) {
    throw new Error('All URLs bad');
  }
  return fetch(urls[i])
    .then(validateHeaders)
    .catch((error) => {
      return getWorkingAudio(i   1);
    });
};
getWorkingAudio()
  .then(handleSuccess)
  .catch(handleError);

It's a pretty bad sign if you often have so many URLs that may be bad due to server load - better to fix/improve the server than to have developers have to work on silly workarounds like this.

CodePudding user response：