vercel-composition-patterns

Replace boolean props with composition by creating explicit variant components like ThreadComposer or EditComposer. Each variant composes shared subcomponents through a compound component structure, eliminating conditional logic and impossible states.

Compound components are structured as a parent provider with subcomponents that access shared state via context instead of props. Consumers compose exactly the pieces they need, such as Composer.Frame, Composer.Input, and Composer.Submit, without hidden conditionals.

Prefer children for composing static structure because they are more readable and compose naturally. Use render props only when the parent needs to pass data back to the child, such as rendering list items with per-item data.

No, React 19 makes ref a regular prop, so forwardRef is unnecessary. The use() hook also replaces useContext() and can be called conditionally, unlike useContext.

Lift state into a provider when sibling components outside the main UI need access to that state or its actions. This avoids prop drilling, useEffect syncing, and ref-based workarounds while keeping UI decoupled from state implementation.