[React Native] V8.14.0 breaks normal fetch behavior

[e-verhoeven]

The following commit seems to have broken the normal fetch() behavior in React Native:

• experiment(native): implement missing Blob/URL/fetch APIs by @CodyJasonBennett in experiment(native): implement missing Blob/URL/fetch APIs #2982

It seems like the Polyfill(s) overwrites global behavior that results in broken fetch responses using RN's default fetch() API. After importing the library and calling my own https endpoints using fetch, the await response.json() throws an Unexpected identifier "object" error and the arrayBuffer of my response seems to be empty.

It's been a hell of a ride tracing this back to react-three-fiber 8.14.0 :) Downgrading to 8.13.9 seems to resolve the issue.

[CodyJasonBennett]

Are you using fetch as part of a loader or generally? I'm inclined to revert those changes and forgo react-native's networking stack for other reasons, but what makes this more concerning than just R3F is this has been upstreamed in facebook/react-native#39276. Can you share a simple test case? I'll need to get this straightened on both ends.

[e-verhoeven]

Hi Cody,

What I'm doing is just rendering a component with a three-fiber canvas within a parent component that also calls several of our own backend API's (just normal HTTPS endpoints with JSON responses). Exactly the same calls that would normally successfully execute (i.e. unpack the response using await reponse.json() or await response.arrayBuffer()) in any other place in the app, will fail as soon as I import stuff from the react-three-fiber/native 8.14.0 in that child component.

We're on:
"react": "18.2.0",
"react-native": "0.72.4",
"expo-gl": "^13.2.0",
"expo": "^49.0.10"

[CodyJasonBennett]

I'm not able to reproduce locally, testing with data:application/json;base64,eyJ0ZXN0Ijp0cnVlfQ== as JSON, but I published v8.14.4 which unsets the Blob global. See if that helps and if you have a withstanding test case I can take a closer look.

[CodyJasonBennett]

I've since merged #3030 and #3042 in 8.14.6, the latter reverting changes from 8.14 directly. Let me know if the first was helpful for future reference, but it resolves this issue surely as of now.