fix(android): Prevent breadcrumb loss from numeric timestamp ClassCastException

CHANGELOG.md

@@ -14,6 +14,10 @@
 - Record XHR request/response headers and (optionally) bodies in Mobile Session Replay. Opt in via `mobileReplayIntegration` with `networkDetailAllowUrls` to capture headers; set `networkCaptureBodies: true` to also capture bodies. Other options: `networkDetailDenyUrls`, `networkRequestHeaders`, `networkResponseHeaders`. Authorization-like headers are always stripped, bodies are capped at ~150 KB. Covers XHR-based clients like `axios`; fetch will follow. See [Network Details](https://docs.sentry.io/platforms/react-native/session-replay/#network-details) for details. ([#6288](https://github.com/getsentry/sentry-react-native/pull/6288))
 - Warn during dev builds when multiple versions of Sentry JS SDK are detected ([#6269](https://github.com/getsentry/sentry-react-native/pull/6269))
 
+### Fixes
+
+- Fix Android `ClassCastException` when syncing breadcrumbs with a numeric timestamp to the native scope ([#6308](https://github.com/getsentry/sentry-react-native/pull/6308))
+
 ### Dependencies
 
 - Bump Android SDK from v8.43.1 to v8.43.2 ([#6273](https://github.com/getsentry/sentry-react-native/pull/6273))

packages/core/RNSentryAndroidTester/app/src/test/java/io/sentry/rnsentryandroidtester/RNSentryBreadcrumbTest.kt

@@ -68,6 +68,21 @@ class RNSentryBreadcrumbTest {
         assertNotNull(actual.timestamp)
     }
 
+    @Test
+    fun parsesNumericTimestampWithoutDiscardingBreadcrumb() {
+        // The JS SDK stamps `timestamp` as a number (epoch seconds), which arrives over the bridge
+        // as a Double. The native deserializer expects an ISO-8601 string, so without normalization
+        // this throws a ClassCastException and the whole breadcrumb is discarded (see #6306).
+        val map = JavaOnlyMap()
+        map.putString("message", "testMessage")
+        map.putDouble("timestamp", 1_700_000_000.5)
+        val actual = RNSentryBreadcrumb.fromMap(map, logger)
+        assertEquals("testMessage", actual.message)
+        assertEquals("react-native", actual.origin)
+        assertNotNull(actual.timestamp)
+        assertEquals(1_700_000_000_500L, actual.timestamp.time)
+    }
+
     @Test
     fun reactNativeForMissingOrigin() {
         val map =

packages/core/android/src/main/java/io/sentry/react/RNSentryBreadcrumb.java

@@ -4,9 +4,11 @@
 import com.facebook.react.bridge.ReadableMapKeySetIterator;
 import com.facebook.react.bridge.ReadableType;
 import io.sentry.Breadcrumb;
+import io.sentry.DateUtils;
 import io.sentry.ILogger;
 import io.sentry.SentryLevel;
 import io.sentry.util.MapObjectReader;
+import java.util.Date;
 import java.util.Map;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -42,7 +44,18 @@ public static String getCurrentScreenFrom(ReadableMap from) {
   @NotNull
   public static Breadcrumb fromMap(ReadableMap from, @NotNull ILogger logger) {
     try {
-      final @NotNull MapObjectReader reader = new MapObjectReader(toDeepHashMap(from));
+      final @NotNull Map<String, Object> map = toDeepHashMap(from);
+
+      // The JS SDK stamps `timestamp` as a number (epoch seconds), which arrives over the bridge as
+      // a Double. The native Breadcrumb deserializer expects an ISO-8601 string, so normalize it
+      // before deserializing to avoid a ClassCastException.
+      final @Nullable Object timestamp = map.get("timestamp");
+      if (timestamp instanceof Number) {
+        final long millis = (long) (((Number) timestamp).doubleValue() * 1000);
+        map.put("timestamp", DateUtils.getTimestamp(new Date(millis)));
+      }
+
+      final @NotNull MapObjectReader reader = new MapObjectReader(map);
       final @NotNull Breadcrumb breadcrumb =
           new Breadcrumb.Deserializer().deserialize(reader, logger);