fix(ios): honor _experiments.enableUnhandledCPPExceptionsV2 on v8

Same dead-code issue as the profiling fix — `SentrySDKWrapper` parses
`_experiments.enableUnhandledCPPExceptionsV2`, but `RNSentryStart` (the
live init path since v8.0.0) does not. Port the handling into the
`_experiments` block just introduced for `profilingOptions`, and add
enabled/disabled/default XCTest coverage on `RNSentryStart`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: antonis

CHANGELOG.md

@@ -15,6 +15,7 @@
 ### Fixes
 
 - Fix iOS UI profiling options being silently ignored since v8.0.0 ([#6012](https://github.com/getsentry/sentry-react-native/pull/6012))
+- Fix `_experiments.enableUnhandledCPPExceptionsV2` being silently ignored on iOS since v8.0.0
 
 ## 8.8.0
 

packages/core/RNSentryCocoaTester/RNSentryCocoaTesterTests/RNSentryTests.m

@@ -1470,6 +1470,60 @@ - (void)testStartCreateOptionsWithDictionaryEmptyExperimentsDoesNotInstallConfig
 }
 #endif
 
+- (void)testStartCreateOptionsWithDictionaryEnableUnhandledCPPExceptionsV2Enabled
+{
+    NSError *error = nil;
+
+    NSDictionary *_Nonnull mockedReactNativeDictionary = @{
+        @"dsn" : @"https://abcd@efgh.ingest.sentry.io/123456",
+        @"_experiments" : @ {
+            @"enableUnhandledCPPExceptionsV2" : @YES,
+        },
+    };
+    SentryOptions *actualOptions =
+        [RNSentryStart createOptionsWithDictionary:mockedReactNativeDictionary error:&error];
+
+    XCTAssertNotNil(actualOptions, @"Did not create sentry options");
+    XCTAssertNil(error, @"Should not pass no error");
+    XCTAssertTrue(actualOptions.experimental.enableUnhandledCPPExceptionsV2,
+        @"enableUnhandledCPPExceptionsV2 should be enabled");
+}
+
+- (void)testStartCreateOptionsWithDictionaryEnableUnhandledCPPExceptionsV2Disabled
+{
+    NSError *error = nil;
+
+    NSDictionary *_Nonnull mockedReactNativeDictionary = @{
+        @"dsn" : @"https://abcd@efgh.ingest.sentry.io/123456",
+        @"_experiments" : @ {
+            @"enableUnhandledCPPExceptionsV2" : @NO,
+        },
+    };
+    SentryOptions *actualOptions =
+        [RNSentryStart createOptionsWithDictionary:mockedReactNativeDictionary error:&error];
+
+    XCTAssertNotNil(actualOptions, @"Did not create sentry options");
+    XCTAssertNil(error, @"Should not pass no error");
+    XCTAssertFalse(actualOptions.experimental.enableUnhandledCPPExceptionsV2,
+        @"enableUnhandledCPPExceptionsV2 should be disabled");
+}
+
+- (void)testStartCreateOptionsWithDictionaryEnableUnhandledCPPExceptionsV2Default
+{
+    NSError *error = nil;
+
+    NSDictionary *_Nonnull mockedReactNativeDictionary = @{
+        @"dsn" : @"https://abcd@efgh.ingest.sentry.io/123456",
+    };
+    SentryOptions *actualOptions =
+        [RNSentryStart createOptionsWithDictionary:mockedReactNativeDictionary error:&error];
+
+    XCTAssertNotNil(actualOptions, @"Did not create sentry options");
+    XCTAssertNil(error, @"Should not pass no error");
+    XCTAssertFalse(actualOptions.experimental.enableUnhandledCPPExceptionsV2,
+        @"enableUnhandledCPPExceptionsV2 should default to disabled");
+}
+
 - (void)testStartEventFromSentryCocoaReactNativeHasOriginAndEnvironmentTags
 {
     SentryEvent *testEvent = [[SentryEvent alloc] init];

packages/core/ios/RNSentryStart.m

@@ -100,9 +100,15 @@ + (SentryOptions *_Nullable)createOptionsWithDictionary:(NSDictionary *_Nonnull)
         }
     }
 
-    // Configure iOS UI Profiling from _experiments.profilingOptions
+    // Configure experimental options from _experiments
     NSDictionary *experiments = mutableOptions[@"_experiments"];
     if (experiments != nil && [experiments isKindOfClass:[NSDictionary class]]) {
+        BOOL enableUnhandledCPPExceptions =
+            [experiments[@"enableUnhandledCPPExceptionsV2"] boolValue];
+        [RNSentryExperimentalOptions setEnableUnhandledCPPExceptionsV2:enableUnhandledCPPExceptions
+                                                         sentryOptions:sentryOptions];
+
+        // Configure iOS UI Profiling
         NSDictionary *profilingOptions = experiments[@"profilingOptions"];
         if (profilingOptions != nil && [profilingOptions isKindOfClass:[NSDictionary class]]) {
             [RNSentryExperimentalOptions configureProfilingWithOptions:profilingOptions