```yaml
name: require-unique-id-props
description: Ensure unique key props are provided when mapping arrays to React elements
globs: ['**/*.tsx', '**/*.jsx']
alwaysApply: true
```
When mapping arrays to React elements, each element must have a unique key prop to help React efficiently update the DOM.
❌ Bad - Missing key prop:
```jsx
{items.map((item) => (
{item.name}
))}
```
✅ Good - With key prop:
```jsx
{items.map((item) => (
{item.name}
))}
```
Keys should be stable, predictable, and unique among siblings.