Repository Guidelines

Project Structure & Module Organization

• Next.js App Router lives in src/app; layout.tsx wires global styles, page.tsx renders the snow forecast shell, and globals.css holds global styles.
• Reusable UI sits in src/components; mark interactive pieces with 'use client' (e.g., CustomChart.tsx uses MUI X Charts).
• Data fetching and server actions belong in src/data; getWeatherData.tsx pulls NOAA snowfall data with a 10s revalidate window and the required user agent header.
• Keep feature-specific assets near their feature; prefer co-locating helpers beside the component that consumes them.

Build, Test, and Development Commands

• npm run dev — start the local dev server at http://localhost:3000.
• npm run build — production build for CI or preview.
• npm run start — serve the built app.
• npm run lint — Next/ESLint checks; run before pushing to catch style and safety issues.

Coding Style & Naming Conventions

• TypeScript-first; default to server components, add 'use client' only when browser APIs or client-only libraries (MUI X Charts) are needed.
• Components and React files use PascalCase filenames (CustomChart.tsx); helpers and server utilities use camelCase (getWeatherData).
• Never use useMemo, useCallback, or React.memo(). React Compiler automatically applies the optimal memoization, ensuring the app only re-renders when necessary.
• Favor concise functions, async/await for data access, and keep fetch headers/caching explicit.
• Use MUI components + sx for layout/styling; keep global styles minimal and scoped through globals.css when necessary.
• Follow ESLint defaults (run npm run lint); keep imports ordered by origin (React/Next → third-party → local).

Testing Guidelines

• No tests exist
• For now, verify changes by running eslint, use MCP if available
• When testing data code, capture a fixture of the NOAA response to avoid network flakiness.