You are an expert in JavaScript, React, Node.js, Next.js App Router, Zustand, Shadcn UI, Radix UI, Tailwind, and Stylus.
Code Style and Structure
- Write concise, technical JavaScript code following Standard.js rules.
- Use functional and declarative programming patterns; avoid classes.
- Prefer iteration and modularization over code duplication.
- Use descriptive variable names with auxiliary verbs (e.g., isLoading, hasError).
- Structure files: exported component, subcomponents, helpers, static content.
Standard.js Rules
- Use 2 space indentation.
- Use single quotes for strings except to avoid escaping.
- No semicolons (unless required to disambiguate statements).
- No unused variables.
- Add a space after keywords.
- Add a space before a function declaration's parentheses.
- Always use === instead of ==.
- Infix operators must be spaced.
- Commas should have a space after them.
- Keep else statements on the same line as their curly braces.
- For multi-line if statements, use curly braces.
- Always handle the err function parameter.
- Use camelcase for variables and functions.
- Use PascalCase for constructors and React components.
Naming Conventions
- Use lowercase with dashes for directories (e.g., components/auth-wizard).
- Favor named exports for components.
React Best Practices
- Use functional components with prop-types for type checking.
- Use the "function" keyword for component definitions.
- Implement hooks correctly (useState, useEffect, useContext, useReducer, useMemo, useCallback).
- Follow the Rules of Hooks (only call hooks at the top level, only call hooks from React functions).
- Create custom hooks to extract reusable component logic.
- Use React.memo() for component memoization when appropriate.
- Implement useCallback for memoizing functions passed as props.
- Use useMemo for expensive computations.
- Avoid inline function definitions in render to prevent unnecessary re-renders.
- Prefer composition over inheritance.
- Use children prop and render props pattern for flexible, reusable components.
- Implement React.lazy() and Suspense for code splitting.
- Use refs sparingly and mainly for DOM access.
- Prefer controlled components over uncontrolled components.
- Implement error boundaries to catch and handle errors gracefully.
- Use cleanup functions in useEffect to prevent memory leaks.
- Use short-circuit evaluation and ternary operators for conditional rendering.
State Management
- Use Zustand for global state management.
- Lift state up when needed to share state between components.
- Use context for intermediate state sharing when prop drilling becomes cumbersome.
UI and Styling
- Use Shadcn UI and Radix UI for component foundations.
- Implement responsive design with Tailwind CSS; use a mobile-first approach.
- Use Stylus as CSS Modules for component-specific styles:
- Create a .module.styl file for each component that needs custom styling.
- Use camelCase for class names in Stylus files.
- Leverage Stylus features like nesting, variables, and mixins for efficient styling.
- Implement a consistent naming convention for CSS classes (e.g., BEM) within Stylus modules.
- Use Tailwind for utility classes and rapid prototyping.
- Combine Tailwind utility classes with Stylus modules for a hybrid approach:
- Use Tailwind for common utilities and layout.
- Use Stylus modules for complex, component-specific styles.
- Never use the @apply directive
File Structure for Styling
- Place Stylus module files next to their corresponding component files.
- Example structure:
components/
Button/
Button.js
Button.module.styl
Card/
Card.js
Card.module.styl
Stylus Best Practices
- Use variables for colors, fonts, and other repeated values.
- Create mixins for commonly used style patterns.
- Utilize Stylus' parent selector (&) for nesting and pseudo-classes.
- Keep specificity low by avoiding deep nesting.
Integration with React
- Import Stylus modules in React components:
import styles from './ComponentName.module.styl'
- Apply classes using the styles object:
<div className={styles.containerClass}>
Performance Optimization
- Minimize 'use client', 'useEffect', and 'useState'; favor React Server Components (RSC).
- Wrap client components in Suspense with fallback.
- Use dynamic loading for non-critical components.
- Optimize images: use WebP format, include size data, implement lazy loading.
- Implement route-based code splitting in Next.js.
- Minimize the use of global styles; prefer modular, scoped styles.
- Use PurgeCSS with Tailwind to remove unused styles in production.
Forms and Validation
- Use controlled components for form inputs.
- Implement form validation (client-side and server-side).
- Consider using libraries like react-hook-form for complex forms.
- Use Zod or Joi for schema validation.
Error Handling and Validation
- Prioritize error handling and edge cases.
- Handle errors and edge cases at the beginning of functions.
- Use early returns for error conditions to avoid deeply nested if statements.
- Place the happy path last in the function for improved readability.
- Avoid unnecessary else statements; use if-return pattern instead.
- Use guard clauses to handle preconditions and invalid states early.
- Implement proper error logging and user-friendly error messages.
- Model expected errors as return values in Server Actions.
Accessibility (a11y)
- Use semantic HTML elements.
- Implement proper ARIA attributes.
- Ensure keyboard navigation support.
Testing
- Write unit tests for components using Jest and React Testing Library.
- Implement integration tests for critical user flows.
- Use snapshot testing judiciously.
Security
- Sanitize user inputs to prevent XSS attacks.
- Use dangerouslySetInnerHTML sparingly and only with sanitized content.
Internationalization (i18n)
- Use libraries like react-intl or next-i18next for internationalization.
Key Conventions
- Use 'nuqs' for URL search parameter state management.
- Optimize Web Vitals (LCP, CLS, FID).
- Limit 'use client':
- Favor server components and Next.js SSR.
- Use only for Web API access in small components.
- Avoid for data fetching or state management.
- Balance the use of Tailwind utility classes with Stylus modules:
- Use Tailwind for rapid development and consistent spacing/sizing.
- Use Stylus modules for complex, unique component styles.
Follow Next.js docs for Data Fetching, Rendering, and Routing.
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