fix: let error boundaries handle chunk loading failures

[MikitasK]

Summary

Closes #1428

MF v.2 can surface failed remote chunk load through synthetic module factory. Resulting ChunkLoadError passes through Re.Pack's guarded __webpack_require__, where it's reported as fatal. This bypasses dynamic-import rejection path preventing React.lazy Error Boundaries from handling failure & causing Release app to terminate

chunk_loading_error_on_prod.mp4

PR change keeps Metro-compatible guarded require but allows ChunkLoadError to propagate to dynamic-import promise. promise can then reject normally & be handled by nearest Error Boundary

• startup module errors are still reported through ErrorUtils.reportFatalError
• optional nested require() failures remain catchable
• ordinary module errors retain existing fatal behavior
• Webpack & Rspack module-cache behavior is unchanged

fixed_chunk_loading_error_on_prod.mp4

Test plan

In repo root:

1. pnpm --filter @callstack/repack typecheck
2. pnpm --filter @callstack/repack run build:js
3. pnpm --filter @callstack/repack run build:ts
4. pnpm --filter integration-test test -- RepackTargetPlugin.test.ts

In apps/tester-federation-v2:

1. build host prod bundle:

pnpm exec react-native bundle \
  --config config.host-app.mts \
  --platform android \
  --entry-file src/host/index.js \
  --dev=false \
  --bundle-output build/host-app/android/output-local/index.android.bundle \
  --assets-dest build/host-app/android/output-local/res

2. build mini-app prod bundle:

pnpm exec react-native bundle \
  --config config.mini-app.mts \
  --platform android \
  --entry-file src/mini/index.js \
  --dev=false \
  --bundle-output build/mini-app/android/output-local/index.android.bundle \
  --assets-dest build/mini-app/android/output-local/res

3. serve build/mini-app on port 8082:

python3 -m http.server 8082 --directory build/mini-app

4. verify that the manifest & exposed chunk are initially available (both requests should return HTTP 200):

curl -I http://localhost:8082/android/mf-manifest.json
curl -I http://localhost:8082/android/__federation_expose_MiniAppNavigator.chunk.bundle

5. rename exposed chunk to simulate deployment with missing chunk:

mv \
  build/mini-app/android/__federation_expose_MiniAppNavigator.chunk.bundle \
  build/mini-app/android/__federation_expose_MiniAppNavigator.chunk.bundle.disabled

6. verify that chunk now returns HTTP 404:

curl -I http://localhost:8082/android/__federation_expose_MiniAppNavigator.chunk.bundle

7. adb reverse tcp:8082 tcp:8082
8. build & launch Release app:

pnpm exec react-native run-android \
  --mode release \
  --appId com.tester.federationV2 \
  --no-packager

9. open Gallery in app

Expected result:

• missing chunk request returns HTTP 404
• logcat contains ChunkLoadError
• Gallery renders "Failed to load Mini App" fallback
• logcat doesn't contain any fatal exceptions

[changeset-bot]

🦋 Changeset detected

Latest commit: 4b946c9

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 6 packages

Name	Type
@callstack/repack	Patch
@callstack/repack-plugin-expo-modules	Patch
@callstack/repack-plugin-nativewind	Patch
@callstack/repack-plugin-reanimated	Patch
@callstack/repack-dev-server	Patch
@callstack/repack-init	Patch

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[vercel]

@MikitasK is attempting to deploy a commit to the Callstack Team on Vercel.

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[dannyhw]

how do these changes to copy the properties impact the fix? or does it solve some other issue?

[MikitasK]

good catch, thanks 👍 basically, these changes don't directly impact 'chunk load error' fix.
so I just reverted it to keep this PR focused on chunk loading error & not brake any existing logic

[whydidoo]

@MikitasK hey, ChunkLoadError is not the only error that can cause this issue. For example, we encountered Module Federation errors containing a #RUNTIME-\d+ code that also crashed the app, so we added a check for them in our code as well. Could we check for and handle these errors here too?