Response contructor is incompatible with other browser implementations

[spearmootz]

if you use new Response directly and use 204 responses you get the following issue.

new Response('', Init)
fails on chrome because it expects no body. you can do

new Response(null, init)
fails on Firefox because body cannot be null

but you can do in both firefox, chrome, Edge, safari
new Response(init);

but that fails when using this polyfill.

[spearmootz]

i get around it with the following code.

const polyfilled = fetch.toString().includes('XMLHttpRequest');
if (polyfilled) {
  const getClassOf = Function.prototype.call.bind(Object.prototype.toString);
  const isClassOf = (instance, className) => getClassOf(instance).split(' ')[1].includes(className);
  const PolyfilledResponse = window.Response;
  window.Response = (first, second) => {
    if (isClassOf(first, 'Object')) {
      return new PolyfilledResponse(null, first);
    }

    return new PolyfilledResponse(first, second);
  }
}

[mislav]

Thanks for reporting! In the meantime, I think you can use new Response(undefined, {status: 204}) as a workaround in your app. It's a shame null doesn't work in Firefox; is this known to Mozilla?

[spearmootz]

so my original assumption that doing new Response(options) works on other browsers. it actually returns a response that is a 200, no matter if you did 204 or 400. so it will always be resp.ok

[dgraham]

Reopening to track updating our Response constructor to match the specification changes.

We need to handle the optional first BodyInit argument here.

https://github.com/github/fetch/blob/7a692dc519a3a110526a26c7e252f99991510c2a/fetch.js#L377-L380