coding-standards

Apply the standards during code reviews, refactoring, and new module creation by checking naming, immutability, error handling, and type safety rules. The Skill provides concrete good and bad examples for each rule so violations are easy to spot.

Use functional components with typed props interfaces, default parameter values, and clear variant patterns. Extract reusable logic into custom hooks like useDebounce, and prefer functional state updates to avoid stale state in async scenarios.

Use Zod schemas to define expected shapes with constraints like string lengths and datetime formats. Parse the request body inside a try-catch and return a 400 response with validation details when ZodError is thrown.

Direct mutation breaks React's change detection and causes unpredictable bugs in shared state. Use the spread operator to create updated copies, such as {...user, name: 'New Name'} or [...items, newItem], keeping updates immutable.

Watch for functions over 50 lines, nesting deeper than a few levels, and unexplained magic numbers. Split long functions into smaller units, use early returns to flatten nesting, and replace magic numbers with named constants.