Promise retry

retries.js

// Common pattern of wrapping a library async function in a promise
function retriesAsyncOperation (args, retriesLeft = 5) {
  return new Promise((resolve, reject) => {
    performAsyncOp(args)
      .then(result => resolve(result)
      .catch((error) => {
        if (retriesLeft == 0) {
          reject(error)
        } else {
          // Passing reject as second argument allows outermost promise to fail when retries run out
          retriesAsyncOperation(args, retriesLeft - 1).then(resolve, reject)
        }
      });
  });
}