Can I catch an error from async without using await?

Dealing with unhandled rejected native promises (and async/await uses native promises) is a feature supported now in V8. It’s used in the latest Chrome to output debugging information when a rejected promise is unhandled; try the following at the Babel REPL:

async function executor() {

async function doStuff() {
  console.log("do stuff");
  throw new Error("omg");

function handleException() {
  console.error("Exception handled");

(async function() {
  try {
      await executor();
  } catch(e) {

You see that, even though the exception from doStuff() is lost (because we’re not using await when we call it), Chrome logs that a rejected promise was unhandled to the console:


This is also available in Node.js 4.0+, though it requires listening to a special unhandledRejection event:

process.on('unhandledRejection', function(reason, p) {
    console.log("Unhandled Rejection at: Promise ", p, " reason: ", reason);
    // application specific logging, throwing an error, or other logic here

Leave a Comment