Design Patterns TypeScript Study

A comprehensive study repository for learning and implementing design patterns using TypeScript.

📖 About

This project is a practical study of design patterns implemented in TypeScript. It serves as a reference guide and learning resource for understanding how different design patterns work and when to apply them in real-world scenarios.

🚀 Getting Started

Prerequisites

• Node.js (v14 or higher)
• npm or yarn
• TypeScript knowledge

Installation

1. Clone the repository:

git clone <repository-url>
cd design_patterns_ts_study

2. Install dependencies:

npm install

3. Run the project:

npx ts-node src/index.ts

📁 Project Structure

├── src/
│   ├── index.ts                 # Main entry point
│   └── creational/              # Creational Design Patterns
│       ├── README.md
│       ├── interfaces/
│       │   └── UserSingleton.ts # Interface definitions
│       └── singleton/           # Singleton Pattern Implementation
│           ├── EXPLANATION.md   # Detailed pattern explanation
│           ├── module_a.ts      # Module A example
│           ├── module_b.ts      # Module B example
│           └── database/        # Database singleton examples
│               ├── my-database-function.ts
│               ├── my-database-module.ts
│               └── my-database-singleton.ts
├── package.json
├── tsconfig.json
└── README.md

🎯 Design Patterns Covered

Creational Patterns

✅ Singleton Pattern

• Location: src/creational/singleton/
• Purpose: Ensures a class has only one instance and provides global access to it
• Use Cases:
  • Database connections
  • File servers
  • Print servers
  • Import modules
  • System configuration objects

Key Features:

• Private static instance attribute
• Private constructor to prevent instantiation with new
• Static getter method that creates or returns the existing instance
• Thread-safe implementation

Example Usage:

const database1 = MyDatabaseSingleton.instance;
const database2 = MyDatabaseSingleton.instance;
// database1 === database2 (same instance)

🛠️ Development

Available Scripts

• npm test - Run tests (currently not configured)

Code Quality Tools

The project is configured with:

• TypeScript: For type safety and modern JavaScript features
• ESLint: Code linting with TypeScript support
• Prettier: Code formatting
• ts-node: Direct TypeScript execution

Configuration Files

• tsconfig.json: TypeScript compiler configuration
• .eslintrc: ESLint configuration with TypeScript and Prettier integration

📚 Learning Resources

Each pattern implementation includes:

• Detailed explanations in markdown files
• Practical examples with real-world scenarios
• Code comments explaining the implementation details
• Multiple usage examples demonstrating different approaches

🤝 Contributing

This is a study project, but contributions are welcome! Feel free to:

• Add new design patterns
• Improve existing implementations
• Add more examples and use cases
• Enhance documentation

📝 TODO

• Add more creational patterns (Factory, Builder, Prototype)
• Implement structural patterns (Adapter, Decorator, Facade)
• Add behavioral patterns (Observer, Strategy, Command)
• Include unit tests for all patterns
• Add performance benchmarks
• Create interactive examples

👨‍💻 Author

Dheyson Alves

📄 License

This project is licensed under the ISC License.

🔗 References

• Design Patterns: Elements of Reusable Object-Oriented Software
• TypeScript Documentation
• Refactoring Guru - Design Patterns

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Happy coding and learning! 🎉