Expo Go Accessibility Testing Limits in Managed Workflow

Quick Answer

Expo Go’s fixed native shell ignores any native accessibility changes that come from config plugins or custom modules. Those changes only appear in a dev or production build that includes the same native code.

1. Props & Native Changes Missing in Expo Go

• accessibilityElementsHidden – hidden elements are ignored.
• accessibilityViewIsModal – focus trapping only works when the native hierarchy is built from the plugin.
• Custom UIAccessibilityCustomAction (iOS) or Android AccessibilityService permissions added via a config plugin are not applied in Expo Go.
• Live‑region updates that rely on native AccessibilityNodeInfo (Android) or UIAccessibilityPostNotification (iOS) are not reflected.
• Dynamic type scaling wired into native code is not triggered.

2. Systematic Verification Workflow

1. Build a Development Client

   expo-dev-client init
   expo run:android   # or expo run:ios
   

2. Capture Accessibility Trees
   • Android: adb shell dumpsys accessibility or use the Accessibility Scanner.
   • iOS: Enable VoiceOver and open the Accessibility Inspector in Xcode.
   Export the tree as JSON for both Expo Go and the dev client.
3. Automated UI Tests

   // Detox example
   it('announces button label', async () => {
     await element(by.id('submitButton')).tap();
     await expect(element(by.label('Submit'))).toBeVisible();
   });
   

   Run the same test suite against Expo Go and the dev client; differences indicate a regression.
4. CI Integration Add a step that builds a dev client, runs the accessibility tests, and fails if the tree differs from a baseline snapshot.

3. Documentation & Testing Patterns

• Maintain a README.md#accessibility section that lists required props and native changes.
• Tag commits that touch accessibility with ✅ accessibility and link to the relevant config plugin.
• Keep a dedicated config-plugins/accessibility.ts that centralizes all native tweaks.
• Use a script that compares the current accessibility tree to a stored snapshot.
• When Expo Go updates, run the audit against both the shell and a fresh dev client to surface mismatches early.

Missing Diagnostic Detail

If your project exposes custom accessibility actions via a native module, let us know so we can adjust the verification steps accordingly.