This isn't an issue with your polyfill per se so feel free to close it any time. We recently noticed a number of exceptions in our app stemming from Fetch-intiated PUT requests in MS Edge that lacked a request body.
I did some digging and found that Edge's PUT requests had Content-Length: 0 so the JSON.stringify'd data we send as the body wasn't making it to the server. I also found that PATCH requests fail entirely and are never transmitted.
These requests succeed in every browser I could find that has native Fetch support. They also succeed in browsers that don't when using this polyfill.
I put together small demo Rack app here: https://github.com/javan/fetch-put-patch-demo
I'm curious if you think MS Edge is doing it right and most closely following the spec. And if not, should this polyfill step in and smooth over the inconsistency?
Thanks for your time! ❤️