In-flight promises #async-await #medium

In-flight-promises.js

async (promises) => {
  let inFlight = new Set();
  
  return promises.map((promise) => {
    // Add promise to inFlight Set
    inFlight.add(promise);
    // Delete promise from Set when it is done
    promise.then(() => inFlight.delete(promise));
  });
}