Re: [streams] Tidy up precondition checking in ErrorReadableStream (f6d7882)

f6d78821a8e4142cf8e9b6c42700020111bb17ed

Seems we may hit the assert when a bad strategy is used. Is this included in `must ensure they have obeyed the precondition (listed here as an assert).`?

---
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/streams/commit/f6d78821a8e4142cf8e9b6c42700020111bb17ed#commitcomment-10582068