Offer some patches for fixing SSE for expo SDK 51

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

Thanks for @etler's work for the SDK 51 patch: https://github.com/etler/expo-sse-patch/tree/expo-51-fix His detailed investigation:

• expo/expo#27526 (comment)
• expo/expo#27526 (comment)

Essentially the problem was moved and only shows up in dev builds through eas build, which requires the expo-dev-client.

I picked his ./plugins/withAndroidExpoSSEPatch.ts and just restricted the if condition a bit

- if (true) {
+ if (body.contentType()?.type == "text" && body.contentType()?.subtype == "event-stream" || peeked.request(byteCount + 1)) {

• expo-env-info (anchor)
• expo doctor (anchor)

Related:

• Expo Issue: expo/expo#27526
• event-source-polyfill PR: Yaffle/EventSource#228

Plugins that patch the problems:

• ./plugins/withAndroidExpoSSEPatch.ts

How to use expo plugins: https://docs.expo.dev/config-plugins/plugins-and-mods/

Essentially, the plugin patch consists in:

• checking for content type text/event-stream in https://github.com/expo/expo/blob/5bd5d1695f932b8448950bb5d927a06bca27547c/packages/expo-modules-core/android/src/main/java/expo/modules/kotlin/devtools/ExpoRequestCdpInterceptor.kt#L57

Side note 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.

Reproducing the problem

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

2. Run app WITHOUT the fix

# cleanup
rm -r android node_modules

npm install

# run without the fix
SSE_NO_FIX=true eas build --platform android --profile development --local
# you will be prompted to create an eas project and add the projectId to app.config.ts
 
# once the app is started
adb reverse tcp:3000 tcp:3000 

In app:

1. Press Open Connexion => should do nothing

3. Run app WITH the fix

# cleanup
rm -r android node_modules

npm install

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

# 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.

Appendix

npx expo-env-info:

    expo-env-info 1.2.0 environment info:
    System:
      OS: Linux 6.5 Ubuntu 22.04.4 LTS 22.04.4 LTS (Jammy Jellyfish)
      Shell: 5.8.1 - /bin/zsh
    Binaries:
      Node: 20.13.1 - ~/.nvm/versions/node/v20.13.1/bin/node
      npm: 10.8.1 - ~/.nvm/versions/node/v20.13.1/bin/npm
    SDKs:
      Android SDK:
        API Levels: 34
        Build Tools: 33.0.1, 34.0.0
        System Images: android-34 | Google APIs Intel x86_64 Atom, android-34 | Google Play Intel x86_64 Atom
    npmPackages:
      expo: ^51.0 => 51.0.14 
      react: 18.2.0 => 18.2.0 
      react-dom: 18.2.0 => 18.2.0 
      react-native: 0.74.2 => 0.74.2 
      react-native-web: ~0.19.6 => 0.19.10 
    npmGlobalPackages:
      eas-cli: 10.0.0
    Expo Workflow: managed

npx expo-doctor@latest

✔ Check Expo config for common issues
✔ Check package.json for common issues
✔ Check native tooling versions
✔ Check dependencies for packages that should not be installed directly
✔ Check for common project setup issues
✔ Check npm/ yarn versions
✔ Check for issues with metro config
✔ Check Expo config (app.json/ app.config.js) schema
✔ Check for legacy global CLI installed locally
✔ Check that native modules do not use incompatible support packages
✔ Check that native modules use compatible support package versions for installed Expo SDK
✔ Check that packages match versions required by installed Expo SDK

Didn't find any issues with the project!