Decorator Pattern in Hono

Overview

Add behavior to objects dynamically

Decorator Pattern 1 implementations available

When to Use

When you need to abstract data access logic
When you want to make your code testable
When you need to support multiple data sources
When you want to decouple business logic from infrastructure

Available Implementations

Error Handler

Global error handling with custom error classes

npx hanma add hono-error-handler --framework hono

Custom error classesProduction-safe messagesHTTP exception handling

Basic Example

// Decorator Pattern implementation example
// This shows the basic structure of decorator pattern in Hono

// Define your interface
interface IRepository {
  findAll(): Promise<T[]>;
  findById(id: string): Promise<T | null>;
  create(data: CreateDto): Promise<T>;
  update(id: string, data: UpdateDto): Promise<T>;
  delete(id: string): Promise<void>;
}

// Implement the pattern
class DecoratorRepository implements IRepository {
  async findAll(): Promise<T[]> {
    // Implementation
  }

  async findById(id: string): Promise<T | null> {
    // Implementation
  }

  async create(data: CreateDto): Promise<T> {
    // Implementation
  }

  async update(id: string, data: UpdateDto): Promise<T> {
    // Implementation
  }

  async delete(id: string): Promise<void> {
    // Implementation
  }
}

// Use the pattern
const repository = new DecoratorRepository();
const items = await repository.findAll();

Frequently Asked Questions

What is Decorator Pattern?

Add behavior to objects dynamically. It's a well-established software design pattern that helps organize code for better maintainability and testability.

How does Decorator Pattern work with Hono?

Hono provides excellent support for this pattern through its dependency injection system and middleware composition.

What are the benefits?

Improved testability, separation of concerns, easier maintenance, and flexibility to change implementations without affecting business logic.

When should I avoid this pattern?

For very simple applications with minimal logic, the pattern may add unnecessary complexity. Use judgment based on project requirements.