How to Structure package-notes.md

A well-structured package-notes.md file should serve as a comprehensive reference for your package.json decisions, making it easy for team members (including your future self) to understand the rationale behind dependencies, scripts, and configuration choices.

Recommended Structure

Here's a proven structure that covers all the essential aspects of documenting your package.json:

1. Header Section

Start with basic project information and the purpose of the documentation:

# Package Documentation: [Project Name]

**Last Updated:** [Date]  
**Maintainer:** [Name/Team]  
**Package Version:** [Current Version]

## Purpose
This document explains the decisions and rationale behind our package.json configuration, dependencies, and scripts.

2. Scripts Documentation

Document your npm scripts with clear explanations of what each does and when to use them[1]:

## Scripts

### Development Scripts
- **`npm start`** - Starts the development server with hot reloading
  - Uses: Local development and testing
  - Notes: Runs on port 3000 by default

- **`npm run dev`** - Alternative development command with additional debugging
  - Uses: When you need verbose logging during development
  - Notes: Includes source maps and error reporting

### Build Scripts
- **`npm run build`** - Creates production-ready build
  - Uses: Before deployment or testing production builds
  - Notes: Optimizes and minifies code, outputs to /dist

- **`npm run build:dev`** - Creates development build
  - Uses: Testing build process without minification
  - Notes: Faster than production build, includes debug info

3. Dependencies Documentation

Explain why each major dependency was chosen and any important considerations[2]:

## Dependencies

### Core Dependencies
- **express (^4.18.0)** - Web framework
  - Why: Lightweight, well-documented, large ecosystem
  - Notes: Pinned to major version 4 for stability

- **lodash (^4.17.21)** - Utility library
  - Why: Provides reliable utility functions
  - Notes: Consider tree-shaking in future to reduce bundle size

### Development Dependencies
- **jest (^29.0.0)** - Testing framework
  - Why: Comprehensive testing with good TypeScript support
  - Notes: Configured for React testing in jest.config.js

- **eslint (^8.0.0)** - Code linting
  - Why: Enforces consistent code style
  - Notes: Uses Airbnb config with custom overrides

4. Configuration Decisions

Document important configuration choices and their reasoning:

## Configuration Decisions

### Version Strategy
- **Semantic Versioning**: Following strict semver for public API
- **Dependency Pinning**: Major versions pinned, minor/patch allowed to float
- **Lock Files**: Using package-lock.json for reproducible builds

### Engine Requirements
- **Node.js**: >= 16.0.0 (for ES2022 features)
- **npm**: >= 8.0.0 (for workspaces support)

### Publishing Configuration
- **Main Entry**: `dist/index.js` (compiled output)
- **Types**: `dist/index.d.ts` (TypeScript definitions)
- **Files**: Only includes `dist/`, `README.md`, and `package.json`

5. Environment-Specific Notes

Document any environment-specific considerations:

## Environment Notes

### Development
- Requires `.env.local` file for local API endpoints
- Uses different database connection for testing
- Hot reloading enabled for faster development

### Production
- Environment variables injected via CI/CD
- Logging level set to 'error' only
- Performance monitoring enabled

### Testing
- Uses in-memory database for unit tests
- Separate test environment variables in `.env.test`

6. Troubleshooting Section

Include common issues and solutions:

## Troubleshooting

### Common Issues

**"Module not found" errors after npm install**
- Solution: Clear node_modules and package-lock.json, then reinstall
- Command: `rm -rf node_modules package-lock.json && npm install`

**Scripts fail with permission errors**
- Solution: Check file permissions on script files
- Command: `chmod +x scripts/*.sh`

**Build fails in CI but works locally**
- Solution: Ensure Node.js versions match between local and CI
- Check: `.nvmrc` file matches CI configuration

7. Change Log

Track important changes to package.json:

## Change Log

### 2024-01-15
- Updated React to v18.2.0 for concurrent features
- Added @types/node for better TypeScript support
- Removed deprecated babel-polyfill

### 2024-01-10
- Added husky for pre-commit hooks
- Configured lint-staged for staged file linting
- Updated ESLint configuration for React 18

Best Practices

When maintaining your package-notes.md:

Keep it current: Update the file whenever you modify package.json[2]
Link to external docs: Reference official documentation for complex dependencies
Use consistent formatting: Follow the same structure throughout
Include examples: Show command usage and expected outputs where helpful
Review regularly: Schedule periodic reviews to remove outdated information

Template Section

You can also include a template section for quickly documenting new dependencies:

## Template for New Dependencies

### [Dependency Name] ([Version])
- **Purpose**: [What problem does this solve?]
- **Why chosen**: [Why this library over alternatives?]
- **Configuration**: [Any special setup needed?]
- **Notes**: [Important considerations or limitations]

This structure provides a comprehensive yet maintainable way to document your package.json decisions, making it easy for team members to understand the reasoning behind your choices and quickly find the information they need.

eonist/package-info-best-practice.md