import AwaitLock from 'await-lock';

let lock = new AwaitLock();

async function runSerialTaskAsync() {
  await lock.acquireAsync();
  try {
    // IMPORTANT: Do not return a promise from here because the finally clause
    // may run before the promise settles, and the catch clause will not run if
    // the promise is rejected
  } finally {
    lock.release();
  }
}

import AwaitLock from 'await-lock';

let runSerialTaskAsync = co.wrap(function*() {
  yield lock.acquireAsync();
  try {
    // Run async code in the critical section
  } finally {
    lock.release();
  }
});