fetch timeout

fetch_timeout.js

const CONNECTION_TIMEOUT = 20000;

function getData (url) {
  let timer = null;

  const service = fetch(url)
    .then((response) => {
      clearTimeout(timer);
      return response.json();
    });

  const timeout = new Promise((resolve) => { timer = setTimeout(resolve, CONNECTION_TIMEOUT); })
    .then(() => { throw new Error('Connection timeout'); });

  return Promise.race([service, timeout]);
}