Web Worker for a generic Fetch

fetch-worker.js

/*
 * Fetch Worker
 * Usage:
 *     const fetchWorker = new Worker('./fetch-worker.js');
 *     fetchWorker.postMessage('https://some.api/with-data.json');
 */

self.addEventListener(‘message’,  e => {
    let url = e.data;
    
    fetch(url).then(res => {
        if (res.ok) {
            self.postMessage(res);
        } else {
            throw new Error(’Fetch encountered an error with the server.’);
        }
    }).catch(err => {
        self.postMessage(err.message);
    });
})