Opik Frontend
Architecture Decisions
- •Routing: TanStack Router (file-based)
- •Data fetching: TanStack Query (never raw fetch/useEffect)
- •State: Zustand for global, React state for local
- •Components: shadcn/ui + Radix UI base
- •Forms: React Hook Form + Zod validation
Critical Gotchas
Never useEffect for Data Fetching
typescript
// ❌ BAD
useEffect(() => {
fetch('/api/data').then(setData);
}, []);
// ✅ GOOD
const { data } = useQuery({
queryKey: ['data'],
queryFn: fetchData,
});
Selective Memoization
typescript
// ✅ USE useMemo for: complex computations, large data transforms const filtered = useMemo(() => data.filter(x => x.status === 'active').map(transform), [data] ); // ✅ USE useCallback for: functions passed to children const handleClick = useCallback(() => doSomething(id), [id]); // ❌ DON'T memoize: simple values, primitives, local functions const name = data?.name ?? ''; // No useMemo needed
Zustand Selectors
typescript
// ✅ GOOD - specific selector
const selectedEntity = useEntityStore(state => state.selectedEntity);
// ❌ BAD - selecting entire store causes re-renders
const { selectedEntity, filters } = useEntityStore();
Layer Architecture
code
ui → shared → pages-shared → pages (one-way only)
- •No circular dependencies
- •No cross-page imports
- •After modifying imports:
npm run deps:validate
State Location Decisions
- •URL state: filters, pagination, selected items
- •Zustand: user preferences, cross-component state
- •React state: form inputs, UI toggles
Component Structure
typescript
const Component: React.FC<Props> = ({ prop }) => {
// 1. State hooks
// 2. Queries/mutations
// 3. Memoization (only when needed)
// 4. Event handlers
if (isLoading) return <Loader />;
if (error) return <ErrorComponent />;
return <div>...</div>;
};
Query Patterns
typescript
// Query with params
const { data } = useQuery({
queryKey: [ENTITY_KEY, params],
queryFn: (context) => fetchEntity(context, params),
});
// Mutation with invalidation
const mutation = useMutation({
mutationFn: updateEntity,
onSuccess: () => {
queryClient.invalidateQueries({ queryKey: [ENTITY_KEY] });
},
});
Reference Files
- •forms.md - React Hook Form + Zod patterns
- •ui-components.md - Button variants, typography, dark theme
- •responsive-design.md - Tailwind breakpoints vs useIsPhone
- •testing.md - When to test, Vitest patterns
- •code-quality.md - Lodash imports, naming, deps:validate
- •performance.md - Bundle optimization, rendering, memoization