App Crashes on Exception on Non-critical Path (C++ Exception)

Description

Soft exception thrown in callbacks, e.g., setTimeout incurs a crash. In the reported core dump the signature is "C++ Exception".

Scope:

• Uncontrolled exception in callbacks passed in to setTimeout, <Pressable>, etc;
• Above crashes exist also in less defensive 3rd party libs (extended scope);
• Incidents are also found in ReactFabric::extractEvents.

Steps to reproduce

Code below crashes app 10 secs after bootstrap:

setTimeout(() => {throw new Error('SWW')}, 10000);

Comparable throws in a <Pressable>, etc., can easily reproduce.

React Native Version

0.77.2, 0.79.2

Affected Platforms

Runtime - iOS

Output of npx @react-native-community/cli info

System:
  OS: macOS 15.4
  CPU: (8) arm64 Apple M1 Pro
  Memory: 135.81 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.19.1
    path: ~/.nvm/versions/node/v20.19.1/bin/node
  Yarn:
    version: 1.22.19
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.8.2
    path: ~/.nvm/versions/node/v20.19.1/bin/npm
  Watchman:
    version: 2025.04.28.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.2
    path: /Users/holmes/.rvm/gems/ruby-3.2.0/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.4
      - iOS 18.4
      - macOS 15.4
      - tvOS 18.4
      - visionOS 2.4
      - watchOS 11.4
  Android SDK: Not Found
IDEs:
  Android Studio: 2024.2 AI-242.23726.103.2422.12816248
  Xcode:
    version: 16.3/16E140
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.14
    path: /usr/bin/javac
  Ruby:
    version: 3.2.0
    path: /Users/holmes/.rvm/rubies/ruby-3.2.0/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 18.0.0
    wanted: 18.0.0
  react:
    installed: 19.0.0
    wanted: 19.0.0
  react-native:
    installed: 0.79.2
    wanted: 0.79.2
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Stacktrace or Logs

terminating due to uncaught exception of type facebook::jsi::JSError: ExceptionsManager.reportException raised an exception: Unhandled JS Exception: Error: SWW, js engine: hermes, stack:
anonymous@49376:19
Error: ExceptionsManager.reportException raised an exception: Unhandled JS Exception: Error: SWW, js engine: hermes, stack:
anonymous@49376:19
CoreSimulator 1010.10 - Device: iPhone 16 Pro (A124ADE1-D75C-4F48-A913-0C72B0BC212A) - Runtime: iOS 18.0 (22A3351) - DeviceType: iPhone 16 Pro

MANDATORY Reproducer

https://github.com/ehsemloh/crash-cpp-excetpion

Screenshots and Videos

https://drive.google.com/file/d/1fyPmGmg6MdMOXZHYrm0voWaMNtnmlUOZ/view?usp=sharing

Bắt đầu bằng cách chạy trình tái hiện bắt buộc và theo dõi đường đi của callback từ setTimeout hoặc Pressable qua ExceptionsManager.reportException. So sánh đường đi đó với các sự cố được đề cập trong ReactFabric::extractEvents; hoàn tất khi trình tái hiện không còn kết thúc ứng dụng iOS do một exception từ callback không quan trọng.