[iOS][Fabric] A recycled Fabric iOS view can lose the Selected accessibility trait after reuse

[cgoldsby]

Description

A recycled Fabric iOS view can lose the Selected accessibility trait after reuse.

On Fabric iOS, self.accessibilityTraits is written by two places in RCTViewComponentView updateProps:

• accessibilityTraits: replaces the full bitmask from the role (does not include Selected)
• accessibilityState: ORs in Selected/NotEnabled

Both writers diff against the view's retained props. Retained props survive recycling, so a recycled view diffs new props against stale values from its previous lifecycle.

Example with three lifecycles of one recycled view:

1. Button A (role=button, selected=true): both writers fire. Traits = Button | Selected. ✅
2. Plain view (role=none, selected=false): both writers fire. Traits = None. ✅
3. Button A again (role=button, selected=true): the role changed (none → button), so the traits writer fires and sets Button. But retained props still hold selected=true from lifecycle 1, so the state writer skips. Traits = Button only. Selected is lost. ❌

Steps to reproduce

1. Render two Views with different keys and different roles (role="button" and no role), both with accessibilityState={{ selected: true }}
2. Conditionally render one at a time; toggle between them so Fabric unmounts one and mounts the other (forcing the native view through the recycle pool)
3. Focus the recycled View in Accessibility Inspector
4. The Selected trait is missing

The bug fires when the recycled view's stale _props.selected matches the new value (true → true), so the accessibilityState diff guard skips.

Reproducer Steps

git clone https://github.com/cgoldsby/rn-accessibility-traits-bug.git
cd rn-accessibility-traits-bug
yarn install
cd ios && pod install && cd ..
yarn ios

• Open Accessibility Inspector
• Focus the target View
• Tap "Toggle Role" to switch from role="button" to no role (both selected: true)
• Accessibility Inspector shows the Selected trait is lost

React Native Version

0.86.0

Affected Platforms

Runtime - iOS

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

info Fetching system and libraries information...
System:
  OS: macOS 26.4.1
  CPU: (8) arm64 Apple M1
  Memory: 148.58 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.19.6
    path: ~/.nvm/versions/node/v20.19.6/bin/node
  Yarn:
    version: 1.22.22
    path: /opt/homebrew/bin/yarn
  npm:
    version: 10.8.2
    path: ~/.nvm/versions/node/v20.19.6/bin/npm
  Watchman:
    version: 2025.05.26.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.15.2
    path: /Users/cgoldsby/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.5
      - iOS 26.5
      - macOS 26.5
      - tvOS 26.5
      - visionOS 26.5
      - watchOS 26.5
  Android SDK:
    API Levels:
      - "31"
      - "33"
      - "34"
      - "35"
      - "36"
      - "37"
    Build Tools:
      - 30.0.3
      - 31.0.0
      - 33.0.0
      - 33.0.1
      - 34.0.0
      - 35.0.0
      - 36.0.0
      - 37.0.0
    System Images:
      - android-31 | Android TV ARM 64 v8a
      - android-31 | AOSP ATD ARM 64 v8a
      - android-33 | Android TV ARM 64 v8a
      - android-34 | Android TV ARM 64 v8a
      - android-34 | Google TV ARM 64 v8a
      - android-34 | Google APIs ARM 64 v8a
      - android-35 | Google Play ARM 64 v8a
    Android NDK: Not Found
IDEs:
  Android Studio: 2025.2 AI-252.25557.131.2521.14344949
  Xcode:
    version: 26.5/17F42
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.10
    path: /usr/bin/javac
  Ruby:
    version: 4.0.2
    path: /Users/cgoldsby/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native: Not Found
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: Not found
  newArchEnabled: Not found
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Stacktrace or Logs

N/A

MANDATORY Reproducer

https://github.com/cgoldsby/rn-accessibility-traits-bug

Screenshots and Videos

reproducer.mp4