User Management System

A modular TypeScript project for managing users with file-based JSON storage. The system is designed for extensibility, testability, and clean separation of concerns.

Features

• Add, update, delete, and list users
• Data validation and error handling
• Pluggable storage (JSON file by default)
• Layered architecture (Controller, Service, Storage)
• Simple logging utility

Project Structure

src/
  User.ts                  # User interface/type definition
  UserManager.ts           # (Legacy) User management logic
  validators/
    UserValidator.ts       # User data validation logic
  errors/
    UserError.ts           # Custom error classes
  storage/
    FileStorage.ts         # Abstract file storage
    JsonUserStorage.ts     # JSON file storage implementation
  services/
    UserService.ts         # Business logic for user operations
  controllers/
    UserController.ts      # Controller for user operations
  utils/
    logger.ts              # Simple logger utility
  index.ts                 # Entry point (example usage)

Usage Example

Run the example script:

pnpm install
pnpm ts-node src/index.ts

Example output:

[2025-07-14T12:00:00.000Z] Users created.
[2025-07-14T12:00:00.000Z] All users: [{"id":"1","name":"Alice","age":30,"position":"Developer"}, ...]
[2025-07-14T12:00:00.000Z] User 1: {"id":"1","name":"Alice","age":30,"position":"Developer"}
[2025-07-14T12:00:00.000Z] User 1 updated.
[2025-07-14T12:00:00.000Z] User 2 deleted.
[2025-07-14T12:00:00.000Z] Final users: [{"id":"1","name":"Alice","age":31,"position":"Developer"}]

API Overview

User Interface

interface User {
  id: string;
  name: string;
  age: number;
  position: string;
}

Main Classes

• UserController – High-level API for user operations
• UserService – Business logic and validation
• JsonUserStorage – File-based storage
• UserValidator – Data validation
• UserError – Custom error for user operations

Example: Adding a User

import { UserController } from './controllers/UserController';
const controller = new UserController();
await controller.createUser({ id: '3', name: 'Eve', age: 22, position: 'QA' });

Extending the System

• Add new storage backends by extending FileStorage<T>
• Add new validation rules in UserValidator
• Integrate with a web server or CLI via UserController

Development

• Written in TypeScript
• Modular and testable
• Easily extensible for new features

License

MIT