Custom hooks extract and share component logic. Here's how to build them effectively.
Basic Custom Hook#
Loading code block...
Hook with Parameters#
Loading code block...
Async Hook with Loading State#
Loading code block...
Hook Composition#
Loading code block...
Reducer-Based Hook#
Loading code block...
Testing Custom Hooks#
Loading code block...
Best Practices#
Naming:
✓ Start with "use" prefix
✓ Be descriptive
✓ Match React conventions
✓ Indicate return type
Design:
✓ Single responsibility
✓ Return stable references
✓ Handle cleanup
✓ Support SSR
Performance:
✓ Memoize callbacks
✓ Use lazy initialization
✓ Avoid unnecessary effects
✓ Handle race conditions
Testing:
✓ Test in isolation
✓ Test all states
✓ Test cleanup
✓ Test edge cases
Conclusion#
Custom hooks encapsulate reusable logic cleanly. Start simple, compose smaller hooks into larger ones, and always handle cleanup. Test hooks in isolation using renderHook and consider all states: loading, success, error, and edge cases.