self is not defined in NPM packages imported in a Worker

[oscarotero]

Version: Deno 1.45.5

I have the following code:

// worker.js
import prism from "npm:[email protected]";

console.log(prism);
console.log(self);

That it's executed inside a worker:

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

And this produces the following error:

error: Uncaught (in worker "") (in promise) ReferenceError: self is not defined
    at Object.<anonymous> (file:///Users/oscarotero/Library/Caches/deno/npm/registry.npmjs.org/prismjs/1.29.0/prism.js:11:48)

Looks like the self object is not defined inside Prism npm package. It's accessed here:

var _self = (typeof window !== 'undefined')
	? window   // if in browser
	: (
		(typeof WorkerGlobalScope !== 'undefined' && self instanceof WorkerGlobalScope)
			? self // if in worker
			: {}   // if in node js
	);

Replacing self with globalThis, the script works fine:

var _self = (typeof window !== 'undefined')
	? window   // if in browser
	: (
		(typeof WorkerGlobalScope !== 'undefined' && globalThis instanceof WorkerGlobalScope)
			? globalThis // if in worker
			: {}   // if in node js
	);

The problem seems to exist only in NPM packages, because the following js file run in a Worker doesn't fail:

console.log(self);

[bartlomieju]

Appears to be a regression from #24637 - self should be undefined in the main context, but defined in worker contexts.