Express REST API with TypeScript & OOP

This repository contains a Sample backend REST API. It is built using Express.js and TypeScript, with a strong emphasis on Object-Oriented Programming (OOP) principles and a clean, layered architecture. It uses Prisma as the ORM for interacting with a PostgreSQL database.

Key Features

• Framework: Express.js for building robust APIs.
• Language: TypeScript for type safety and scalability.
• Database: PostgreSQL with Prisma ORM for seamless database interaction.
• Architecture: Clean, layered architecture (Routes, Controllers, Services, Repositories).
• Design Patterns: Utilizes Object-Oriented Programming (OOP) and the Repository Pattern for decoupled, maintainable code.
• Validation: Request validation using Joi to ensure data integrity.
• Security: Password hashing with bcrypt.
• Error Handling: Centralized and custom error handling middleware.

Project Structure

The project follows a modular and scalable structure designed to separate concerns and improve maintainability.

.
├── prisma/             # Prisma schema and database migrations
├── src/
│   ├── base/           # Base classes for controllers and validators
│   ├── common/         # Common TypeScript interfaces
│   ├── controller/     # Express controllers to handle requests and responses
│   ├── db/             # Prisma client instance and common queries
│   ├── repositories/   # Data access layer (interacts with the database)
│   ├── routes/         # API route definitions
│   ├── server/         # Express server setup and initialization
│   ├── services/       # Business logic layer
│   ├── utils/          # Helper functions and custom error classes
│   └── validations/    # Joi validation schemas
├── .env.example        # Example environment variables
├── package.json        # Project dependencies and scripts
└── tsconfig.json       # TypeScript compiler options

Getting Started

Follow these instructions to get a copy of the project up and running on your local machine for development and testing purposes.

Prerequisites

• Node.js (v16 or newer)
• NPM
• A running PostgreSQL database instance

Installation & Setup

1. Clone the repository:

   git clone https://github.com/amanbnl/express-rest-api-using-oops.git
   cd express-rest-api-using-oops

2. Install dependencies:

   npm install

3. Set up environment variables: Create a .env file in the root directory by copying the example file.

   cp .env.example .env

   Open the .env file and update the variables with your database configuration:

   # Your PostgreSQL connection string
   DATABASE_URL="postgresql://<user>:<password>@<host>:<port>/<db_name>"
   
   # Port for the application to run on
   APP_PORT=8000
   
   # Bcrypt salt rounds for password hashing
   SALT_ROUND=10

4. Run database migrations: This command applies the schema defined in prisma/schema.prisma to your database.

   npx prisma migrate dev

5. Start the development server: The server runs using nodemon, which will automatically restart the application upon file changes.

   npm start

   The API will be available at http://localhost:8000 (or the port specified in your .env file).

API Endpoints

The API provides endpoints for user management under the /api/v1/users route.

Method	Endpoint	Description
POST	/api/v1/users	Creates a new user. The role is automatically set to 'customer'.
GET	/api/v1/users	Retrieves a list of all users.
GET	/api/v1/users/:id	Retrieves a single user by their unique ID.
PATCH	/api/v1/users/:id	Updates an existing user's details (full name, email, phone number).
DELETE	/api/v1/users/:id	Deletes a user by their unique ID.

Database Schema

The database schema is managed by Prisma and is defined in the prisma/schema.prisma file. It includes models for users, roles.