fetch implementation does not support streams from the spec - needs implementation in React Native core

[pcowgill]

React Native has not implemented fetch on top of native APIs, and the fetch polyfill built on top of XHR does not support streams where response.body is a getter for a ReadableStream.

React Native version:

0.61.4

Steps To Reproduce

Use fetch and see that response.body is undefined rather than a getter for a ReadableStream according the the fetch spec.

Describe what you expected to happen:

I expected for response.body to be defined.

Related issues

#9629
#12912
JakeChampion/fetch#746 (comment) (cc @MattiasBuelens)

[pcowgill]

React Native also has a Canny board for feature requests I previously was unaware of. If you come across this GitHub issue and care about this feature being prioritized, please feel free to upvote it over there as well. Thanks!

https://react-native.canny.io/feature-requests/p/fetch-streaming-body

[pcowgill]

Let's create a fork of github/fetch under the Facebook org so we can open pull requests against it without worrying about breaking legacy browsers that are using github/fetch.

As discussed here JakeChampion/fetch#746

cc @hugomrdias @cpojer

[pcowgill]

Can we create that fork of github/fetch under the Facebook org?

It looks like improvements to the current fetch solution are getting lots of upvotes on Canny:
https://react-native.canny.io/feature-requests/p/fetch-streaming-body
https://react-native.canny.io/feature-requests/p/implement-fetch-using-native-implementations-instead-of-fetch-on-top-of-xhr

[cpojer]

The Facebook GitHub org only contains project managed by Facebook. It'll mean we have to take care of releases and everything. I'm not sure if that's a good idea, you'll probably be able to move faster on a separate org. What about react-native-community? @alloy can get you set up with that.

[alloy]

@pcowgill If you’re interested in spear-heading that effort in the react-native-community org, please contact me at eloy.de.enige@gmail.com to get the process started.

[pcowgill]

@cpojer @alloy Thanks for getting back to me! I think that could work. @hugomrdias Do you think that will serve our needs?

We should still keep this issue open though, because eventually we'll want to have a spec-compliant implementation of fetch at the native level in React Native.

[alloy]

Just created the fork and added you, @pcowgill https://github.com/react-native-community/fetch

[pcowgill]

@alloy Thanks! After something is published from that fork and we've tested the polyfill thoroughly, we'll want to make a PR to use the new npm package here

react-native/Libraries/Network/fetch.js

Line 16 in 507379f

require('whatwg-fetch');

If anyone else would like to collaborate on that fork, just comment here!

[hugomrdias]

Just created the fork and added you, @pcowgill react-native-community/fetch

can you please add me too, thanks

[pcowgill]

@hugomrdias You should have an invite in your email inbox now. Thanks!