Learn ECMAScript - Second Edition

Introduction to inline web workers

It is possible to create a web worker from a single file without actually having a separate JS file for your web worker. However, I still recommend that you create a different file for your web workers, for the sake of clarity of code and to make it more modular. Modularity is always preferred in programming.

We can make use of blob URLs to actually point data in memory to a URL, and then load the blob URL instead of an actual file URL. Since this URL is generated dynamically only on the user's computer, you do not need to create a separate file for that particular web worker. Here's how we'll do that:

const blob = new Blob(['(',function() {    // web worker code here}.toString(),')()'], { type: 'application/javascript' ...