Blob override is not good enough and clashes with whatwg-fetch npm package

[weizman]

• @vadman97 commented https://github.com/highlight/highlight/issues/3934#issuecomment-1579700793 where he shows multiple issues with Snow integration.
• I was able to reproduce specifically the exception with the [object Blob] thing on LinkedIn (which I believe is the same issue).
  • This happens because LinkedIn uses whatwg-fetch which tries to tell what is the type of a message body parameter.
  • To determine whether it is a Blob, it runs support.blob && Blob.prototype.isPrototypeOf(body) where true indicates it is a Blob.
  • Since our wrap makes Blob inherit from Function instead of Blob, this fails and we end up on a different conclusion which results in a shitstorm basically.
• Moreover, Current implementation is not secure enough.
  • One can get a hold on a Blob instance that is not created via new Blob() and thus bypassing Snow.
  • For example, XHR when configured right responds with a native Blob object which obviously isn't affected by our monkey patching.
• These issues require attention, especially making sure web apps don't break when running on Snow

[weizman]

if disallowing creation of URL object out of Blob/File completely the way Snow does in #88 prevents your application from running correctly, please share so in this issue thread so we can discuss the problem and understand how to best deal with it

[weizman]

Was a complicated one, I prey to god on this one 🙏 #88