SKILL.md
Functional Programming in React
Practical patterns for React apps. No jargon, just code that works.
Detailed Guide
Read [the detailed guide](references/detailed-guide.md) before executing this skill. It retains the complete procedure and reference material. Treat its safety, prerequisites, and validation requirements as mandatory. For focused work, load the relevant sections; for end-to-end work, read the guide completely.
When to Use This Skill
- When building React apps with fp-ts for type-safe state management
- When handling loading/error/success states in data fetching
- When implementing form validation with error accumulation
- When using React 18/19 or Next.js 14/15 with functional patterns
When to Use What
| Situation | Use |
|---|---|
| Value might not exist | Option<T> |
| Operation might fail (sync) | Either<E, A> |
| Async operation might fail | TaskEither<E, A> |
| Need loading/error/success UI | RemoteData<E, A> |
| Form with multiple validations | Either with validation applicative |
| Dependency injection | Context + ReaderTaskEither |
| Prevent re-renders with fp-ts | useMemo or fp-ts-react-stable-hooks |
Limitations
- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.