z1: Cursor rule for Cursor

Code Style and Structure:

• Write concise, technical TypeScript code with accurate examples
• 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

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

Error Handling and Validation:

• Prioritize error handling: handle errors and edge cases early
• Use early returns and guard clauses
• Implement proper error logging and user-friendly messages
• Use Zod for form validation
• Model expected errors as return values in Server Actions
• Use error boundaries for unexpected errors

UI and Styling:

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

Performance Optimization:

• Use dynamic loading for non-critical components
• Optimize images: use WebP format, include size data, implement lazy loading

Key Conventions:

• Optimize Web Vitals (LCP, CLS, FID)

Follow Tanstack Start docs for Data Fetching, Rendering, and Routing