Yarn 2 (Berry)

YARN 2 (Berry) - The Modern Package Manager 🧶

Yarn 2, also known as Berry, is a significant evolution of the original Yarn package manager. It brings improved performance, enhanced security, and new features to JavaScript and Node.js development.

Architecture and Concepts 🏗️

Yarn 2's architecture is designed for efficiency, reliability, and improved developer experience:

• 📁 Plug'n'Play (PnP): A new resolution strategy that replaces node_modules

• 🔒 Zero-Installs: Allows committing dependencies to version control

• 🌐 Workspaces: Improved monorepo support

• 🔧 Constraints: Enforce rules across your project

• 📦 Protocols: Flexible ways to fetch packages

Key Concepts:

• 🚀 Performance: Faster installs and reduced disk usage

• 🔐 Security: Improved package resolution and validation

• 🛠️ Extensibility: Plugin system for custom functionality

• 📜 TypeScript Support: Better integration with TypeScript projects

Yarn 2 Architecture Diagram 📊

Common Yarn 2 Commands 🖥️

Installation:

npm install -g yarn
yarn set version berry

Initialize a new project:

yarn init -2

Add a dependency:

yarn add [package-name]
yarn add [package-name]@[version]
yarn add -D [package-name]  # Add as dev dependency

Remove a dependency:

yarn remove [package-name]

Install all dependencies:

yarn install

Run a script:

yarn [script-name]

Update packages:

yarn up
yarn up [package-name]

Code Snippets 💻

Example package.json:

{
  "name": "my-yarn2-project",
  "version": "1.0.0",
  "dependencies": {
    "express": "^4.17.1"
  },
  "devDependencies": {
    "typescript": "^4.5.4"
  },
  "scripts": {
    "start": "ts-node src/index.ts",
    "build": "tsc",
    "test": "jest"
  }
}

Example TypeScript file (src/index.ts):

import express from 'express';

const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World from Yarn 2 project!');
});

app.listen(port, () => {
  console.log(`Server running at <http://localhost>:${port}`);
});

Running the application:

yarn start

Output:

Server running at <http://localhost:3000>

Deployment Commands 🚀

Here are some common deployment commands:

Build for production:

yarn build

Run tests before deployment:

yarn test

Start in production mode:

yarn start:prod

Add these scripts to your package.json:

{
  "scripts": {
    "build": "tsc",
    "test": "jest",
    "start:prod": "NODE_ENV=production node dist/index.js"
  }
}

Conclusion 🎉

Yarn 2 (Berry) is a powerful and efficient package manager for Node.js projects. Its innovative features like Plug'n'Play and Zero-Installs provide significant improvements in performance and project management. By leveraging Yarn 2's capabilities, developers can create more efficient, secure, and maintainable JavaScript and TypeScript applications.