Next.js 14 Best Practices

# Next.js 14 Best Practices
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## Core Principles
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1. **Separation of Concerns**: Keep components, pages, and API routes organized and focused on a single responsibility.
2. **Reusability**: Design components to be reusable across the application.
3. **Performance Optimization**: Prioritize page loading speed and optimize images, fonts, and other assets.
4. **Accessibility**: Ensure all pages and components are accessible and follow Web Content Accessibility Guidelines (WCAG 2.1).

## Code Style Guidelines
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### Naming Conventions

1. **Component Names**: Use PascalCase for component names (e.g., `HeaderComponent`).
2. **Variable Names**: Use camelCase for variable names (e.g., `userName`).
3. **File Names**: Use kebab-case for file names (e.g., `header-component.js`).

### Typing

1. **Type Annotations**: Use TypeScript type annotations for all variables, function parameters, and return types.
2. **Type Definitions**: Define types for custom components, interfaces, and enums.

### Code Organization

1. **Component Structure**: Keep components in a separate directory (e.g., `components/`).
2. **Page Structure**: Keep pages in a separate directory (e.g., `pages/`).
3. **API Route Structure**: Keep API routes in a separate directory (e.g., `api/`).

## Best Practices
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### Component Development

1. **Use Functional Components**: Prefer functional components over class components.
2. **Use Hooks**: Use React Hooks for state management and side effects.
3. **Avoid Prop Drilling**: Use context API or a state management library to avoid prop drilling.

### Performance Optimization

1. **Use `next/image`**: Use the `next/image` component for image optimization.
2. **Use `next/font`**: Use the `next/font` component for font optimization.
3. **Use Code Splitting**: Use code splitting to reduce bundle sizes.

### Security

1. **Validate User Input**: Validate user input to prevent XSS attacks.
2. **Use Environment Variables**: Use environment variables to store sensitive data.
3. **Use Authentication**: Implement authentication and authorization mechanisms.

### Testing

1. **Write Unit Tests**: Write unit tests for components and API routes.
2. **Write Integration Tests**: Write integration tests for pages and user flows.
3. **Use a Testing Library**: Use a testing library like Jest or Cypress.

## Common Pitfalls to Avoid
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1. **Over-Engineering**: Avoid over-engineering components or features.
2. **Tight Coupling**: Avoid tight coupling between components or modules.
3. **Unused Code**: Remove unused code and dependencies.
4. **Inconsistent Code Style**: Avoid inconsistent code style and formatting.
5. **Unoptimized Images**: Avoid using unoptimized images or assets.

By following these best practices, you can ensure your Next.js 14 application is scalable, maintainable, and performant.