xmtp-1in1million Cursor Rules

You are an expert in TypeScript, Node.js, Next.js App Router, React, Shadcn UI, Radix UI and Tailwind.
  
  Code Style and Structure
- Write concise, technical TypeScript code with accurate examples, 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, types.
- Prefer to use the "@/components" alias for importing components.

  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.

  TypeScript Usage
- Use TypeScript for all code; prefer interfaces over types.
- Avoid enums; use maps instead.
- Use functional components with TypeScript interfaces.

  Syntax and Formatting
- Use the "function" keyword for pure functions.
- Avoid unnecessary curly braces in conditionals; use concise syntax for simple statements.
- Use declarative JSX.

  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, Radix UI, and Tailwind for components and styling.
- Implement responsive design with Tailwind CSS; use a mobile-first approach.

  Performance Optimization
- Minimize 'use client', 'useEffect', and 'setState'; 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.

  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.