synv

🔄 Intelligent environment variable synchronization tool that keeps your .env files in sync with .env.example templates

✨ Features

• Smart Sync: Automatically synchronizes environment variables from .env.example to .env
• Interactive Mode: User-friendly prompts for missing or updated variables
• Preserve Values: Maintains existing values in your .env file
• Comments & Structure: Preserves comments and file structure from templates
• Automatic Backup: Creates backups before modifying .env files
• Fuzzy Search: Intelligent file selection with fuzzy matching
• Type Safety: Built with TypeScript for reliability
• Comprehensive Testing: Full test coverage with Vitest

📦 Installation

# Using npm
npm install -g synv
# Using yarn
yarn global add synv
# Using bun
bun add -g synv

🚀 Quick Start

# Basic usage - syncs .env.example to .env
synv
# Specify custom file paths
synv --env-file .env.local --env-example-file .env.template
# Skip backup creation
synv --skip-backup
# Run in quiet mode (no output)
synv --quiet

📖 Usage

Basic Synchronization

When you run synv without arguments, it will:

1. Look for .env.example in your current directory
2. Look for or create .env in your current directory
3. Create a backup of your existing .env file
4. Synchronize variables from .env.example to .env
5. Prompt you for values of new or empty variables

Command Line Options

Option	Short	Description
--env-example-file <path>	-x	Path to the example environment file (default: .env.example)
--env-file <path>	-e	Path to the environment file (default: .env)
--skip-backup		Skip creating a backup of the .env file
--quiet		Suppress all output

Examples

Sync with custom file names

synv -x .env.template -e .env.local

Sync without creating backup

synv --skip-backup

Use in CI/CD pipelines

synv --quiet --skip-backup

🔧 How It Works

synv intelligently parses your environment files to:

1. Extract Variables: Identifies all environment variables using advanced regex patterns
2. Preserve Structure: Maintains comments, empty lines, and file organization
3. Smart Merging:
   • Keeps existing values from your .env file
   • Adds new variables from .env.example
   • Removes variables no longer in .env.example
   • Updates empty variables with example values
4. Interactive Prompts: When values are missing or need updates, provides user-friendly prompts

Supported Syntax

synv supports various environment variable formats:

# Simple variables
API_KEY=abc123
PORT=3000
# Quoted values
DATABASE_URL="postgresql://localhost:5432/db"
MESSAGE='Hello World'# Empty variables
SECRET_KEY=
UNSET_VAR=
# Variables with special characters
COMPLEX_VAR=value-with-dashes_and_underscores
URL=https://example.com/path?query=value
# Comments are preserved# This is a comment
API_KEY=value # Inline comment# Multi-line values (with quotes)
MULTI_LINE="line1line2line3"

🏗️ Development

Prerequisites

• Node.js 18+ or Bun 1.3.0+
• TypeScript 5.8+

Setup

# Clone the repository
git clone https://github.com/yourusername/synv.git
cd synv
# Install dependencies
bun install
# Run in development mode
bun dev
# Build the project
bun run build

Testing

# Run tests
bun test# Run tests with coverage
bun test:coverage
# Run tests with UI
bun test:ui

Project Structure

synv/
├── src/
│ ├── cli.ts # Main CLI application
│ ├── extract-environment-variables-from-file-lines.ts
│ ├── extract-environment-variable-value-from-line.ts
│ ├── extract-key-value-from-string.ts
│ └── regex.ts # Regex patterns for parsing
├── coverage/ # Test coverage reports
├── dist/ # Compiled output
├── package.json
├── tsconfig.json
└── vitest.config.ts

🧪 Testing

The project includes comprehensive test coverage:

• Unit tests for all parsing functions
• Integration tests for complete workflows
• Edge case handling for various .env formats
• Regex pattern validation

Run the test suite:

bun test

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Development Guidelines

• Write tests for new features
• Maintain existing code style
• Update documentation as needed
• Ensure all tests pass before submitting PR

📝 Changelog

See Releases for a detailed changelog.

🐛 Known Issues

• Multi-line environment values must be properly quoted
• Some edge cases with complex regex patterns in values

🗺️ Roadmap

• Support for .env.local, .env.development, etc.
• Configuration file support (.synvrc)
• Dry-run mode
• Variable validation rules
• Environment variable encryption
• Git hooks integration
• VS Code extension

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Built with cmd-ts for CLI parsing
• Interactive prompts powered by @inquirer/prompts
• Fuzzy search using fuzzbunny
• Styled output with chalk
• Progress indicators via ora

💬 Support

If you have any questions or run into issues, please:

1. Check the FAQ section
2. Search existing issues
3. Create a new issue if needed

👤 Author

Your Name

• GitHub: @yourusername
• Twitter: @yourtwitter

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Made with ❤️ and TypeScript