React patterns Claude Code gets right (and three it gets wrong)

React is a strong area for Claude Code — the patterns are well-established and Claude has seen a lot of React code. But there are a few consistent failure modes to know about. What Claude reliably gets right Component extraction. "Extract this JSX block into a component called X" — Claude does this correctly, handles prop types, moves event handlers appropriately. Hook creation. "Extract this state management into a custom hook." Claude writes clean hooks with correct dependency arrays most of the time. Event handlers. Form handling, click handlers, controlled inputs — these are mechanical and Claude gets them right. Conditional rendering. Standard patterns (short-circuit && , ternary, early return) — Claude picks the appropriate one based on your existing code patterns. Pattern 1: useEffect dependency arrays This is the most consistent mistake. Claude sometimes gets dependency arrays wrong — either missing dependencies or including things that cause infinite loops. Fix: Add to CLAUDE.