Technical planning and discussion

[acostalima]

@cpojer I'm reaching out to follow up on a previous discussion about coming up with a custom Fetch API implementation for React Native at https://github.com/react-native-community/fetch with support for streaming (facebook/react-native#27741). We, MOXY and Protocol Labs, are planning to start this effort shortly and we'd like to know your thoughts on the matter.

In short, what we currently have in mind is as follows:

• Rewrite whatwg-fetch in modern JS.
• Remove XHR out of the equation and implement fetch directly on top of RN's JavaScript Network API exactly for the same reasons outlined at Support for server-sent events (EventSource) discussions-and-proposals#99.
• Assume ReadableStream is available in RN's environment which can be polyfilled with web-streams-polyfill. If ReadableStream is expected to only be used in the context of Fetch, we can probably bundle them together.
• Have tests in place running in an actual RN app on GitHub's CI.

Even if Facebook has no plans to add support for streaming to Fetch for the time being, app developers can easily swap out whatwg-fetch for @react-native-community/fetch manually. Even better would be React Native to do this automatically via some sort of extension or plugin API.

Are there any guidelines which React Native Community packages should conform to? e.g. linter and linting config, CI process config, etc.

CC @satazor @hugomrdias

[hugomrdias]

/cc @autonome

[cpojer]

I think this plan sounds good. If your rewrite does not increase bundle size, we can even consider swapping out whatwg-fetch with the new version.

[tex0l]

I'd be very interested in a stable fetch polyfill that handles streams. By the way, I'm currently considering using https://github.com/joltup/rn-fetch-blob#drop-in-fetch-replacement, I'll debrief you of how it works.

[acostalima]

@cpojer Could you please give me permissions to maintain the repo? Thanks!

[acostalima]

@tex0l Thanks! I wasn't aware rn-fetch-blob had a drop-in fetch replacement. That project looks interesting although its complexity is much superior than what we're trying to achieve here considering its has a strong native component. In our case, we're still going to be limited to text streaming as RN's networking layer cannot stream binary.

[cpojer]

@cpojer Could you please give me permissions to maintain the repo? Thanks!

Done!

[acostalima]

@cpojer I'm not being able to publish the package under react-native-community's organization. Can you give me such permission?

[acostalima]

Ping @cpojer.

[acostalima]

@alloy Can you help? 🙏