Leaderboard Deploy agents

This standard ensures your React components render correctly and efficiently, preventing common pitfalls that cause errors or performance issues.

Proper key usage

Always use stable, unique identifiers as keys when rendering lists:

// ❌ Avoid using array index as key when items can reorder
{payload.map((item, index) => (
  <div key={index}>...</div>
))}

// ✅ Use a unique, stable identifier when available
{payload.map((item) => (
  <div key={item.value || `${item.dataKey}-${item.name}`}>...</div>
))}

Hydration safety

When dealing with components that might render differently on server vs. client, implement hydration safety checks:

const [isMounted, setMounted] = React.useState(false);

React.useEffect(() => {
  setMounted(true);
  // Additional initialization if needed
}, []);

// Avoid hydration mismatch by not rendering on server
if (!isMounted) {
  return null;
}

return <Component {...props} />;

Context-aware rendering

When conditionally showing UI elements or handling state that depends on browser APIs:

1. Check for document/window availability
2. Use useLayoutEffect for DOM measurements
3. Defer client-side-only logic to useEffect

This prevents hydration errors, improves SSR compatibility, and ensures consistent rendering across environments.