# Coding Standards

## Core Standards

- **Languages & Runtimes:** TypeScript 5.9.2, Node.js 20.x LTS
- **Style & Linting:** ESLint with Next.js recommended rules, Prettier for formatting
- **Test Organization:** Co-located tests with component files (Component.test.tsx)

## Critical Rules

- **Never use console.log in production code** - use proper logging
- **All database queries must use Prisma client** - no direct SQL
- **API responses must follow Next.js patterns** - no custom response formats
- **All external inputs must be validated** - use Zod schemas
- **Authentication checks required** - use session validation middleware
- **Image optimization mandatory** - use Next.js Image component
- **Accessibility compliance** - follow WCAG 2.1 AA guidelines

## Language-Specific Guidelines

### TypeScript Specifics

- **Strict Mode:** Enable strict TypeScript compiler options
- **Type Safety:** Prefer types over interfaces for internal types
- **Null Handling:** Use optional chaining and nullish coalescing
- **Async/Await:** Always handle promise rejections appropriately