📘 express-rest-api-practice

A TypeScript-based REST API built with Express.js, designed as a practice implementation for learning modern Node.js API development patterns.
This project demonstrates clean architecture principles, type safety, and professional development tooling while maintaining simplicity suitable for educational purposes.

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🚀 Project Overview

This project serves as a learning-focused REST API implementation, emphasizing:

• Type Safety: Leveraging TypeScript for robust type definitions.
• Clean Architecture: Separation of concerns across controllers, routes, and data layers.
• Mock Data Infrastructure: In-memory data stores for development and testing.
• Testing with Mocha: Includes unit and integration testing using mocha and Node’s native assert module.
• Professional Tooling: ESLint, Prettier, nodemon, and ts-node-dev for a clean and productive dev workflow.

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🏗️ Architecture

The application follows a layered architecture pattern with clear separation of concerns:

src/
├── controllers/       // Route handlers (CRUD logic)
├── infrastructure/    // Mock data generators and stores
├── routes/            // API route definitions
├── services/          // Shared logic and abstractions
├── types/             // TypeScript interfaces and models
├── tests/             // Unit/integration test specs
└── index.ts           // Application entry point

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🧪 Testing Setup

This project uses mocha with native assert for writing and running tests.
Test files are named using the .spec.ts convention and organized under /tests.

📜 Test Scripts

# Run all tests
npm run test

# Run only unit tests
npm run test:unit

# Run only integration tests
npm run test:integration

# Run with coverage (if integrated later with nyc)
npm run test:coverage

You can organize your test files by prefixing them accordingly (e.g., user.unit.spec.ts, user.integration.spec.ts).

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📋 Development Tasks

Here’s a checklist of current and pending work:

✅ Core Functionality

• GET all users (/users)
• GET user by ID (/users/:id)
• POST new user
• PUT update user
• DELETE user

✅ Mock Data System

• Centralized store for users
• Generator functions for users and user details
• UserDetails linked to user by ID

🧪 Testing

• Unit tests for controllers
• Integration tests for full request flow
• Error cases and edge test coverage
• Service logic testing (if applicable)

🛠️ Planned Improvements

• Add middleware for validation using JOI
• Add error handling middleware
• Extract service logic into reusable modules
• Implement proper response structure for all endpoints

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🛠️ Development Environment

Prerequisites

• Node.js (v18+ recommended)
• npm

Installation

git clone https://github.com/Robertcego/express-rest-api-practice.git
cd express-rest-api-practice
npm install

Running the Server

npm run dev

Server will run on http://localhost:3000 or your custom PORT defined in .env.

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📦 Available Scripts

"scripts": {
  "dev": "nodemon",
  "lint": "eslint . --ext .ts",
  "lint:fix": "eslint . --ext .ts --fix",
  "format": "prettier --write .",
  "test": "mocha -r ts-node/register tests/**/*.spec.ts",
  "test:unit": "mocha -r ts-node/register tests/unit/**/*.spec.ts",
  "test:integration": "mocha -r ts-node/register tests/integration/**/*.spec.ts",
  "test:coverage": "nyc npm run test"
}

Ensure to install nyc if using coverage: npm install --save-dev nyc

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📚 API Reference

Health Check

• GET /health – returns { status: 'ok' }

Users

• GET /users – returns array of users
• GET /users/:id – returns user details
• POST /users – adds new user
• PUT /users/:id – updates user
• DELETE /users/:id – removes user

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✅ Code Quality Tools

• ESLint – static code analysis
• Prettier – formatting consistency
• ts-node-dev – dev server with hot-reload
• nodemon – watches file changes
• Mocha – testing framework
• Assert – native Node.js assertion

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📄 License

This project is licensed under the MIT License.

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🙌 Acknowledgements

This project is part of a personal learning journey into backend development and clean architecture patterns in Node.js with TypeScript. Feel free to fork, explore, and adapt!