cherry-pick(Reanimated): Guard for undefined style in Jest utils#8955
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MatiPl01 merged 1 commit into4.2-stablefrom Feb 16, 2026
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## Summary
When writing a component it's common to have undefined as a value in
array of styles. For example:
```tsx
interface Props {
style?: ViewStyle
}
function MyComponent({ style }: Props) {
const animatedStyles = useAnimatedStyles...
return <Animated.View style={[style, animatedStyles]} />
}
```
Jest utils' getCurrentStyle will try to retrieve a value from undefined
resulting in:
```
TypeError: Cannot use 'in' operator to search for 'jestAnimatedValues' in undefined
```
## Test plan
```tsx
interface Props {
style?: ViewStyle
}
function MyComponent({ style }: Props) {
const animatedStyles = useAnimatedStyles(() => ({ width: '100%' }});
return <Animated.View testID="my-component" style={[style, animatedStyles]} />
}
```
```tsx
it('Should ignore undefined in array of styles', () => {
const { getByTestId } = render(<MyComponent />);
expect(getByTestId("my-component")).toHaveAnimatedStyle({ width: '100%' });
// passes without type errors
});
```
MatiPl01
requested review from
kmagiera,
piaskowyk and
tomekzaw
as code owners
tjzel
approved these changes
Feb 16, 2026
MatiPl01
deleted the
@matipl01/cherry-pick/undefined-in-styles-array-jest
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cherry-pick of the #8878