JavaScript AbortController example for custom async function

example.js

function getUserById(userId, signal) {
  if (signal.aborted) {
    return Promise.reject(new DOMException('The API request was aborted.', 'AbortError'));
  }
  
  return new Promise(function(resolve, reject) {
    const jobTimeout = setTimeout(function() {
      signal.removeEventListener('abort', abortHandler);
      resolve({ id: userId, name: 'John' });
    }, 3000);
    
    const abortHandler = function() {
      clearTimeout(jobTimeout);
      reject(new DOMException('The API request was aborted.', 'AbortError'));
    };
    
    signal.addEventListener('abort', abortHandler);
  });
}

(async function() {
  const abortController = new AbortController();
  
  setTimeout(function() {
    abortController.abort();
  }, 1000);
  // or test what happens when already aborted
  //abortController.abort();
  
  try {
    const user = await getUserById(123, abortController.signal);
    
    console.info(user);
  } catch (e) {
    if (e instanceof DOMException && e.name === 'AbortError') {
      console.error('The request was aborted.', e);
    } else {
      console.error('There was unexpected error.', e);
    }
  }
})();