React Patterns

Core React patterns for component design, state management, and optimization.

State Philosophy

Avoid state variables. Prefer derived values and props. Scope state to the smallest subtree that needs it. Use discriminated unions for complex state.

See state-management.md for:

• Derived values over state

• Component boundaries for state scoping

• Context API patterns

• Zustand for complex state

• State machines over multiple useState

Memoization

Required for any O(n) operation. Memoize atomically to minimize dependency arrays. Use Loader/Inner pattern to narrow types before useMemo.

See memoization.md for:

• When to useMemo

• Atomic memoization

• useCallback for handlers

• Loader/Inner pattern for type narrowing

Conditional Logic

Use affirmative logic, explicit conditionals, and ternaries over && . Early returns for guard clauses.

See conditional-logic.md for:

• Affirmative logic

• Explicit conditionals

• Conditional rendering

• Type narrowing with conditionals

• Early returns