Showcase fix of event-source-polyfill. Expo issue is FIXED.

For expo SDK 50, find the reproduction & resolution in branch expo-50
For expo SDK 51, find the reproduction & resolution in branch expo-51

Related:

• event-source-polyfill PR: Yaffle/EventSource#228

About event-source-polyfill

Had to patch package event-source-polyfill as, while in release variant, it crashes the application when there is a connexion error. More there: Yaffle/EventSource#228 (comment)
That is a side issue and doesn't remove the fact that expo and react-native are not letting the sse streams through.

Run Example

1. Run server

# runs npm install within server-sse/
npm run server:setup

# runs local express server on port 3000 or PORT env
npm run server:start

3. Run app

# cleanup
rm -r android node_modules

npm install

# build the app
eas build --platform android --profile development --local
# you will be prompted to create an eas project and add the projectId to app.config.ts

# sideload apk to your device / emulator

# once the app is started
adb reverse tcp:3000 tcp:3000 

In app:

1. Press Open Connexion => should print

   [type: open]
   [type: message
   data: {"num": 1}]
   [type: message
   data: {"num": 2}]
   etc.