Runtime crash with @react-navigation/elements CSS template literal

[Babayev03]

Bug: uniwind transformer causes runtime crash with @react-navigation/elements

Environment

• Expo SDK 54
• React Native 0.81.5 (New Architecture enabled)
• uniwind (latest)
• @react-navigation/native-stack ^7.8.6
• @react-navigation/elements 2.9.3

Error

TypeError: Cannot convert undefined value to object

Runtime crash when importing @react-navigation/elements (directly or via @react-navigation/native-stack).

Root Cause

The CSS template literal in @react-navigation/elements/lib/module/PlatformPressable.js conflicts with uniwind's Metro transformer:

const css = String.raw;
const CSS_TEXT = css`
  .__react-navigation_elements_Pressable_hover {
    position: absolute;
    ...
  }
`;

Reproduction

1. Create Expo project with React Navigation 7 and uniwind
2. Enable package exports (required for React Navigation 7):

   config.resolver.unstable_enablePackageExports = true

3. Import any navigator from @react-navigation/native-stack
4. App crashes at runtime

Tested Configurations

Configuration	Result
No uniwind + package exports	✅ Works
uniwind + package exports	❌ Crashes
uniwind + no package exports	❌ Crashes
Custom transformer skipping @react-navigation	❌ Crashes
Empty CSS file with uniwind	❌ Crashes

Workaround / Resolution

Option 1: Yarn Patch (Recommended)

1. Start the patch:

   yarn patch @react-navigation/elements

2. Edit lib/module/PlatformPressable.js in the temp folder - replace lines 97-144 with:

   // PATCHED: Removed CSS template literal that conflicts with uniwind
   const HoverEffect = ({ color, hoverOpacity = 0.08, activeOpacity = 0.16 }) => {
     if (Platform.OS !== 'web' || color == null) {
       return null;
     }
     return null;
   };

3. Commit the patch:

   yarn patch-commit -s <temp-folder-path>

4. Run yarn install to apply

This patch survives yarn install, npx expo prebuild, and reinstalls.

Option 2: Fix in uniwind

uniwind should handle/skip CSS template literals in node_modules packages to avoid conflicts with third-party libraries.

Expected Behavior

uniwind should handle or skip files containing CSS template literals from third-party packages without causing runtime crashes.

---

This issue was created with the assistance of Claude Code.

[github-actions]

This issue has been automatically closed because it lacks a clear, minimal reproduction that we can use to verify the reported bug.

[jpudysz]

Hey there! 👋

Thanks for reporting this issue. We'd love to help get this sorted out for you.
Could you provide a reproduction? It really helps us debug and fix things faster when we can see exactly what's happening. A minimal repo or code sandbox would be perfect.