function workerFunction() {
    this.addEventListener('message', (e) => {
        console.log('log2: ', e);
        fetchUrl(e.data);
    })

    const fetchUrl = (url) => {
        fetch(url)
            .then((response) => {
                console.log(response);
                return response.json();
            })
            .then((jsonObj) => {
                this.postMessage(jsonObj);
                setTimeout(() => fetchUrl(url), 500);
            })
            .catch((err) => {
                console.error(err);
            });
    }
}


var dataObj = '(' + workerFunction + ')();';
var blob = new Blob([dataObj]);
var blobURL = URL.createObjectURL(blob, {
    type: 'application/javascript; charset=utf-8'
});


window.worker = new Worker(blobURL);
worker.postMessage('https://httpbin.org/ip');
worker.onmessage = function(e) {
  console.info('new stuff:', e.data);
}

const button = document.getElementById('stop')
button.addEventListener('click', () => {
    worker.terminate();
});