fix(android): identify the screen appear event by name instead of class

[TaduJR]

📢 Type of change

• Bugfix
• New feature
• Enhancement
• Refactoring

📜 Description

RNSentryReactFragmentLifecycleTracer waited for the react-native-screens appear event by comparing its canonical class name:

if ("com.swmansion.rnscreens.events.ScreenAppearEvent"
    .equals(event.getClass().getCanonicalName())) {

Class names are not stable once R8 optimization is on. React Native Event subclasses share a superclass and a constructor signature, which makes them candidates for merging, and R8 collapses a group of them into one class that answers to a single name. It also rewrites the compared string literal to that name, so the comparison then matches every event in the group rather than one.

The event is now identified by Event.getEventName(), which React Native documents as "the name of this event as registered in JS". react-native-screens registers topAppear as the onAppear prop, so the name is part of its public contract and cannot change without breaking it. Unoptimized builds behave exactly as before.

The sibling check against com.swmansion.rnscreens.ScreenStackFragment is left as is. androidx.fragment ships a consumer rule that keeps public Fragment subclasses with a public no-arg constructor, and Android requires that constructor for fragment recreation, so that class is never merged.

💡 Motivation and Context

Fixes #6691
With R8 optimization enabled, ui.load.initial_display closes on whichever merged event dispatches first rather than on the screen appear event. topWillAppear always precedes topAppear, and events such as topFocus and topAttached can precede both, so time to initial display is reported shorter than it was. Nothing throws, and every diagnostic on this path logs at SentryLevel.DEBUG, so the data is wrong silently.

This affects any app that enables optimization, which AGP 9 makes the default by dropping support for the ProGuard file that carried -dontoptimize.

Reproduction: REPRO_URL. Four dependencies, no patched libraries, the R8 that AGP ships. There ScreenAppearEvent is merged into React Native's own DrawerClosedEvent, and the merged class holds 22 event names behind one class name.

💚 How did you test it?

Added unit tests to RNSentryReactFragmentLifecycleTracerTest, which previously covered listener registration but not which event triggers the first draw. One asserts that topAppear registers the first draw listener and removes the event listener, one asserts that topWillAppear does neither.

The reported behaviour was confirmed by disassembling the release dex of the reproduction, where the compared literal had been rewritten to the merged class name.

📝 Checklist

• I added tests to verify changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• All tests passing.
• Public API changes reviewed by another Mobile SDK team member or implemented according to the develop docs spec.
• No breaking changes.

🔮 Next steps

An alternative that needs no code change is to ship -keep class com.swmansion.rnscreens.events.ScreenAppearEvent as a consumer ProGuard rule in the SDK. That keeps the class name intact but leaves the identity check dependent on the optimizer, which is why matching by event name is proposed instead.

[alwx]

Hey @TaduJR,

Thanks for submitting this PR! I've added a small comment to the code, and I think that except this really small thing, everything looks good for me.

[TaduJR]

Hi @alwx

Thanks so much for reviewing.

Addressed your concern.

TIA.