fix(core): Retry native module resolution to prevent silent event drops (#5981)

* fix(core): Retry native module resolution to prevent silent event drops

The RNSentry TurboModule reference is resolved once at module load time.
In production Hermes bytecode builds, JS execution can start before the
TurboModule registry is fully populated, causing getRNSentryModule() to
return undefined permanently. This silently disables native transport
and drops all events.

Re-resolve the native module in isNativeAvailable() if the initial
resolution returned undefined. By the time Sentry.init() calls this
method, TurboModules are registered and the module resolves correctly.

Fixes #5508

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: antonis

CHANGELOG.md

@@ -16,6 +16,7 @@
 
 ### Fixes
 
+- Retry native module resolution to prevent silent event drops in production Hermes builds ([#5981](https://github.com/getsentry/sentry-react-native/pull/5981))
 - Lazy-load Metro internal modules to prevent Expo 55 import errors ([#5958](https://github.com/getsentry/sentry-react-native/pull/5958))
 - Fix app start transaction profile offset by using the actual profiling start timestamp instead of the adjusted app start time ([#5962](https://github.com/getsentry/sentry-react-native/issues/5962))
 - Use React `componentStack` as fallback when error has no stack trace on Android ([#5965](https://github.com/getsentry/sentry-react-native/pull/5965))

packages/core/src/js/wrapper.ts

@@ -45,7 +45,7 @@ export function getRNSentryModule(): Spec | undefined {
     : NativeModules.RNSentry;
 }
 
-const RNSentry: Spec | undefined = getRNSentryModule();
+let RNSentry: Spec | undefined = getRNSentryModule();
 
 export interface Screenshot {
   data: Uint8Array;
@@ -649,6 +649,9 @@ export const NATIVE: SentryNativeWrapper = {
   },
 
   isNativeAvailable(): boolean {
+    if (!RNSentry) {
+      RNSentry = getRNSentryModule();
+    }
     return this._isModuleLoaded(RNSentry);
   },
 

packages/core/test/wrapper.test.ts

@@ -1208,4 +1208,38 @@ describe('Tests Native Wrapper', () => {
       });
     });
   });
+
+  describe('isNativeAvailable', () => {
+    test('retries module resolution if initially undefined', () => {
+      // Simulate the race condition: RNSentry was undefined at module load time
+      // but becomes available when isNativeAvailable() is called during init()
+      let mockModule: Spec | undefined = undefined;
+
+      jest.resetModules();
+      jest.doMock('react-native', () => ({
+        NativeModules: {
+          get RNSentry() {
+            return mockModule;
+          },
+        },
+        Platform: { OS: 'ios' },
+      }));
+      // Ensure TurboModules path is not used so NativeModules.RNSentry is checked
+      jest.doMock('../src/js/utils/environment', () => ({
+        isTurboModuleEnabled: () => false,
+      }));
+
+      // eslint-disable-next-line @typescript-eslint/no-var-requires
+      const { NATIVE: isolatedNATIVE } = require('../src/js/wrapper');
+
+      // Initially unavailable (simulates race condition)
+      expect(isolatedNATIVE.isNativeAvailable()).toBe(false);
+
+      // Native module becomes available (TurboModule registered)
+      mockModule = RNSentry;
+
+      // isNativeAvailable retries and finds it
+      expect(isolatedNATIVE.isNativeAvailable()).toBe(true);
+    });
+  });
 });