Execute dynamic Script in Worker.

const func = '() => {const promise = sec => new Promise((resolve, reject) => setTimeout(() => resolve(["hello", sec]), sec * 1000)); promise(4).then(([msg, sec]) => self.postMessage(`${msg} after ${sec} seconds`))}';

const dataObj = `self.postMessage((${func})());`; 
const data = new Blob([dataObj], {type: 'application/javascript; charset=utf-8'});
const uri = URL.createObjectURL(data);
const worker = new Worker(`data:application/javascript,${encodeURIComponent(dataObj)}`);
worker.onmessage = function(e) {
    console.log('Worker: ', e.data);
};