feat: Add experimental flag enableUnhandledCPPExceptionsV2 on iOS

Author: antonis

packages/core/RNSentryCocoaTester/RNSentryCocoaTesterTests/RNSentryTests.mm

@@ -239,6 +239,82 @@ - (void)testCreateOptionsWithDictionarySpotlightZero
     XCTAssertFalse(actualOptions.enableSpotlight, @"Did not disable spotlight");
 }
 
+- (void)testCreateOptionsWithDictionaryEnableUnhandledCPPExceptionsV2Enabled
+{
+    RNSentry *rnSentry = [[RNSentry alloc] init];
+    NSError *error = nil;
+
+    NSDictionary *_Nonnull mockedReactNativeDictionary = @{
+        @"dsn" : @"https://abcd@efgh.ingest.sentry.io/123456",
+        @"_experiments" : @ {
+            @"enableUnhandledCPPExceptionsV2" : @YES,
+        },
+    };
+    SentryOptions *actualOptions = [rnSentry createOptionsWithDictionary:mockedReactNativeDictionary
+                                                                   error:&error];
+
+    XCTAssertNotNil(actualOptions, @"Did not create sentry options");
+    XCTAssertNil(error, @"Should not pass no error");
+
+    id experimentalOptions = [actualOptions valueForKey:@"experimental"];
+    XCTAssertNotNil(experimentalOptions, @"Experimental options should not be nil");
+
+    BOOL enableUnhandledCPPExceptions =
+        [[experimentalOptions valueForKey:@"enableUnhandledCPPExceptionsV2"] boolValue];
+    XCTAssertTrue(
+        enableUnhandledCPPExceptions, @"enableUnhandledCPPExceptionsV2 should be enabled");
+}
+
+- (void)testCreateOptionsWithDictionaryEnableUnhandledCPPExceptionsV2Disabled
+{
+    RNSentry *rnSentry = [[RNSentry alloc] init];
+    NSError *error = nil;
+
+    NSDictionary *_Nonnull mockedReactNativeDictionary = @{
+        @"dsn" : @"https://abcd@efgh.ingest.sentry.io/123456",
+        @"_experiments" : @ {
+            @"enableUnhandledCPPExceptionsV2" : @NO,
+        },
+    };
+    SentryOptions *actualOptions = [rnSentry createOptionsWithDictionary:mockedReactNativeDictionary
+                                                                   error:&error];
+
+    XCTAssertNotNil(actualOptions, @"Did not create sentry options");
+    XCTAssertNil(error, @"Should not pass no error");
+
+    id experimentalOptions = [actualOptions valueForKey:@"experimental"];
+    XCTAssertNotNil(experimentalOptions, @"Experimental options should not be nil");
+
+    BOOL enableUnhandledCPPExceptions =
+        [[experimentalOptions valueForKey:@"enableUnhandledCPPExceptionsV2"] boolValue];
+    XCTAssertFalse(
+        enableUnhandledCPPExceptions, @"enableUnhandledCPPExceptionsV2 should be disabled");
+}
+
+- (void)testCreateOptionsWithDictionaryEnableUnhandledCPPExceptionsV2Default
+{
+    RNSentry *rnSentry = [[RNSentry alloc] init];
+    NSError *error = nil;
+
+    NSDictionary *_Nonnull mockedReactNativeDictionary = @{
+        @"dsn" : @"https://abcd@efgh.ingest.sentry.io/123456",
+    };
+    SentryOptions *actualOptions = [rnSentry createOptionsWithDictionary:mockedReactNativeDictionary
+                                                                   error:&error];
+
+    XCTAssertNotNil(actualOptions, @"Did not create sentry options");
+    XCTAssertNil(error, @"Should not pass no error");
+
+    // Test that when no _experiments are provided, the experimental option defaults to false
+    id experimentalOptions = [actualOptions valueForKey:@"experimental"];
+    XCTAssertNotNil(experimentalOptions, @"Experimental options should not be nil");
+
+    BOOL enableUnhandledCPPExceptions =
+        [[experimentalOptions valueForKey:@"enableUnhandledCPPExceptionsV2"] boolValue];
+    XCTAssertFalse(
+        enableUnhandledCPPExceptions, @"enableUnhandledCPPExceptionsV2 should default to disabled");
+}
+
 - (void)testPassesErrorOnWrongDsn
 {
     RNSentry *rnSentry = [[RNSentry alloc] init];

packages/core/ios/RNSentry.mm

@@ -225,6 +225,17 @@ - (SentryOptions *_Nullable)createOptionsWithDictionary:(NSDictionary *_Nonnull)
     // Failed requests can only be enabled in one SDK to avoid duplicates
     sentryOptions.enableCaptureFailedRequests = NO;
 
+    NSDictionary *experiments = options[@"_experiments"];
+    if (experiments != nil && [experiments isKindOfClass:[NSDictionary class]]) {
+        BOOL enableUnhandledCPPExceptions =
+            [experiments[@"enableUnhandledCPPExceptionsV2"] boolValue];
+        id experimentalOptions = [sentryOptions valueForKey:@"experimental"];
+        if (experimentalOptions) {
+            [experimentalOptions setValue:@(enableUnhandledCPPExceptions)
+                                   forKey:@"enableUnhandledCPPExceptionsV2"];
+        }
+    }
+
     return sentryOptions;
 }
 

packages/core/src/js/options.ts

@@ -253,6 +253,17 @@ export interface BaseReactNativeOptions {
      * This will be removed in the next major version.
      */
     replaysOnErrorSampleRate?: number;
+
+    /**
+     * Experiment: A more reliable way to report unhandled C++ exceptions in iOS.
+     *
+     * This approach hooks into all instances of the `__cxa_throw` function, which provides a more comprehensive and consistent exception handling across an app’s runtime, regardless of the number of C++ modules or how they’re linked. It helps in obtaining accurate stack traces.
+     *
+     * - Note: The mechanism of hooking into `__cxa_throw` could cause issues with symbolication on iOS due to caching of symbol references.
+     *
+     * @default false
+     */
+    enableUnhandledCPPExceptionsV2?: boolean;
   };
 
   /**

samples/react-native/src/App.tsx

@@ -171,6 +171,9 @@ Sentry.init({
   // This should be disabled when manually initializing the native SDK
   // Note that options from JS are not passed to the native SDKs when initialized manually
   autoInitializeNativeSdk: true,
+  _experiments: {
+    enableUnhandledCPPExceptionsV2: true,
+  },
 });
 
 const Stack = isMobileOs