S42-Core Dependencies Class

• Dependencies Class Documentation
  • Features
  • API Documentation
    • Methods
      • add<DEP>(name: string, dep: DEP): void
      • get<DEP>(name: string): DEP | null
      • remove(name: string): boolean
      • clear(): void
      • has(name: string): boolean
  • Example Usage
    • Registering and Retrieving Dependencies
    • Removing and Clearing Dependencies
  • Use Cases
  • Error Handling
  • License

Dependencies Class Documentation

The Dependencies class is a utility designed to manage dependencies in a centralized and controlled manner. It allows you to register, retrieve, and remove dependencies by name, making it ideal for modular applications.

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Features

• Centralized Dependency Management: Register and retrieve dependencies globally.
• Type Safety: Supports TypeScript generics for type-safe dependency management.
• Error Handling: Prevents duplicate dependency registration.

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API Documentation

Methods

add<DEP>(name: string, dep: DEP): void

Registers a new dependency with a unique name.

• Parameters:
  • name (string): The unique name of the dependency.
  • dep (any): The dependency instance or object to register.
• Throws:
  • An error if a dependency with the same name already exists.

get<DEP>(name: string): DEP | null

Retrieves a registered dependency by its name.

• Parameters:
  • name (string): The name of the dependency to retrieve.
• Returns:
  • The instance of the dependency if found, or null if it does not exist.

remove(name: string): boolean

Removes a registered dependency by its name.

• Parameters:
  • name (string): The name of the dependency to remove.
• Returns:
  • true if the dependency was successfully removed, false if it did not exist.

clear(): void

Clears all registered dependencies.

has(name: string): boolean

Checks if a dependency with the specified name exists.

• Parameters:
  • name (string): The name of the dependency to check.
• Returns:
  • true if the dependency exists, false otherwise.

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Example Usage

Registering and Retrieving Dependencies

import { Dependencies } from 's42-core';

// Register a dependency
Dependencies.add('database', { connectionString: 'mongodb://localhost:27017' });

// Check if the dependency exists
if (Dependencies.has('database')) {
  console.log('Database dependency exists.');
}

// Retrieve the dependency
const dbConfig = Dependencies.get<{ connectionString: string }>('database');
console.log('Connection String:', dbConfig?.connectionString);

Removing and Clearing Dependencies

// Remove a specific dependency
Dependencies.remove('database');

// Clear all dependencies
Dependencies.clear();

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Use Cases

• Service Management: Store shared services such as database instances, HTTP clients, or configurations.
• Dependency Injection: Simplify dependency injection across different parts of the application.
• Unit Testing: Mock dependencies for isolated testing scenarios.

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Error Handling

The add method will throw an error if you attempt to register a dependency with a name that already exists. Ensure that names are unique within your application:

try {
  Dependencies.add('database', {});
  Dependencies.add('database', {}); // Throws an error
} catch (error) {
  console.error(error.message);
}

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License

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