aj-geddes/design-patterns-implementation

Design Patterns Implementation

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Apply proven design patterns to create maintainable, extensible, and testable code architectures.

When to Use

• Solving common architectural problems
• Making code more maintainable and testable
• Implementing extensible plugin systems
• Decoupling components
• Following SOLID principles
• Code reviews identifying architectural issues

Quick Start

Minimal working example:

class DatabaseConnection {
  private static instance: DatabaseConnection;
  private connection: any;

  private constructor() {
    this.connection = this.createConnection();
  }

  public static getInstance(): DatabaseConnection {
    if (!DatabaseConnection.instance) {
      DatabaseConnection.instance = new DatabaseConnection();
    }
    return DatabaseConnection.instance;
  }

  private createConnection() {
    return {
      /* connection logic */
    };
  }
}

// Usage
const db1 = DatabaseConnection.getInstance();
const db2 = DatabaseConnection.getInstance();
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

| Guide | Contents | |---|---| | Singleton Pattern | Singleton Pattern | | Factory Pattern | Factory Pattern | | Observer Pattern | Observer Pattern | | Strategy Pattern | Strategy Pattern | | Decorator Pattern | Decorator Pattern | | Repository Pattern | Repository Pattern | | Dependency Injection | Dependency Injection |

Best Practices

✅ DO

• Choose patterns that solve actual problems
• Keep patterns simple and understandable
• Document why patterns were chosen
• Consider testability
• Follow SOLID principles
• Use dependency injection
• Prefer composition over inheritance

❌ DON'T

• Apply patterns without understanding them
• Over-engineer simple solutions
• Force patterns where they don't fit
• Create unnecessary abstraction layers
• Ignore team familiarity with patterns