Modern Best Practice React Components

Rendering & Derivation

• PREFER computing derived values inline or via helper functions
• Use useMemo() sparingly and only for proven performance issues
• AVOID premature optimization
• Keep render logic deterministic and free of side effects

Event Handling

• AVOID in-line event handlers in JSX

  • PREFER:

    function handleClick() {
      // ...
    }
    
    <button onClick={handleClick} />;
    

  • Over:

    <button
      onClick={() => {
        /* ... */
      }}
    />
    

• Name handlers clearly (handleSubmit, handleChange, handleClose)

• Keep handlers small; extract complex logic into helpers

Effects, Data, and Side Effects

• AVOID effects for:
  • Derived state
  • Data transformations
  • Event-based logic that can live in handlers
• If side effects are unavoidable, keep them minimal, isolated, and well-documented
• Prefer framework-level or external abstractions (routers, data libraries) over raw effects

Props & Composition

• PREFER composition over configuration
• AVOID excessive boolean props; prefer expressive APIs
• Use children intentionally and document expected structure
• Keep prop names semantic and predictable

Performance & Stability

• PREFER stable references only when required (not by default)
• AVOID unnecessary memoization (memo, useCallback) unless absolutely required
• Keep keys stable and meaningful when rendering lists

General Principles

• Write code for humans first, compilers second
• Prefer explicitness over cleverness
• Optimize for readability and long-term maintenance
• If a pattern feels complex, reconsider the component boundary