Many use cases around import.meta.url are based on relative loading of sibling paths to import.meta.url.

These naturally end up quite unwieldy, for example loading a worker in the same folder:

new Worker(import.meta.url + '/../worker.js', { type: 'module' });

or even:

new Worker(new URL('./worker.js', import.meta.url).href, { type: 'module' });

Just like Node.js supports both __filename and __dirname, if we had cross-platform support for import.meta.urlBase (name to be bikeshed further), then this could be simplified to:

new Worker(`import.meta.urlBase + '/worker.js', { type: 'module' });

This could help in simplifying conventions around these sibling fetch cases.