Inventory Management System

A RESTful API for managing product inventory with real-time stock tracking, low stock alerts, and CRUD operations for products.

What This Project Does

This inventory management system provides:

• Product Management: Create, read, update, and delete products
• Stock Management: Increase/decrease stock quantities with transaction safety
• Low Stock Monitoring: Track products below threshold levels
• Data Validation: Input validation using Zod schemas
• Error Handling: Comprehensive error handling and logging
• API Testing: Complete test suite with Jest and Supertest

Tech Stack

Technology	Version	Use Case
Node.js	Latest	Runtime environment
TypeScript	^5.9.2	Type-safe JavaScript development
Express.js	^5.1.0	Web framework for REST API
Prisma	^6.16.2	Database ORM and migrations
PostgreSQL	Latest	Primary database
Zod	^4.1.11	Runtime type validation
Winston	^3.17.0	Logging and monitoring
Jest	^29.7.0	Testing framework
Supertest	^7.1.4	HTTP assertion testing
CORS	^2.8.5	Cross-origin resource sharing
Swagger JSDoc	^6.2.8	API documentation generation
Swagger UI Express	^5.0.1	Interactive API documentation

Prerequisites

• Node.js (v18 or higher)
• PostgreSQL database
• npm or yarn package manager

Database Schema

model Product {
  id                  Int      @id @default(autoincrement())
  name                String
  description         String
  stock_quantity      Int
  low_stock_threshold Int
  created_at          DateTime @default(now())
  updated_at          DateTime @updatedAt
}

Installation & Setup

1. Clone the repository

   git clone https://github.com/manikanta5827/inventory_management.git
   cd inventory_management

2. Install dependencies

   npm install

3. Environment Setup Create a .env file in the root directory:

   DATABASE_URL="postgresql://username:password@localhost:5432/inventory"
   PORT=8080

4. Database Migration

   # Generate Prisma client
   npx prisma generate
   
   # Run database migrations
   npx prisma migrate deploy

5. Start the application

   # Development mode
   npm run dev
   
   # Production mode
   npm run build
   npm start

6. Access Swagger Documentation Once the server is running, visit: http://localhost:8080/api-docs

API Documentation

The project includes comprehensive Swagger/OpenAPI documentation:

• Swagger UI: Visit http://localhost:8080/api-docs when the server is running
• Interactive Testing: Test all endpoints directly from the Swagger UI
• Schema Validation: Complete request/response schemas with validation rules
• Error Codes: Detailed error response documentation

Features:

• Complete API endpoint documentation
• Request/response examples
• Schema definitions with validation rules
• Interactive API testing interface
• Organized by tags (Products, Inventory)

Running Tests

# Run all tests
npm test

API Endpoints

Products

Method	Endpoint	Description
POST	/api/v1/products	Create a new product
GET	/api/v1/products	Get all products
GET	/api/v1/products/:id	Get product by ID
PUT	/api/v1/products/:id	Update product
DELETE	/api/v1/products/:id	Delete product

Inventory

Method	Endpoint	Description
PUT	/api/v1/inventory/:id/stock/increase	Increase stock quantity
PUT	/api/v1/inventory/:id/stock/decrease	Decrease stock quantity
GET	/api/v1/inventory/low-stock	Get low stock products

Request/Response Examples

Create Product

POST /api/v1/products
Content-Type: application/json

{
  "name": "Samsung Galaxy S25",
  "description": "Latest smartphone with advanced features",
  "stock_quantity": 100,
  "low_stock_threshold": 10
}

Increase Stock

PUT /api/v1/inventory/1/stock/increase
Content-Type: application/json

{
  "amount": 50
}

Get Low Stock Products

GET /api/v1/inventory/low-stock

Project Structure

src/
├── controllers/     # Business logic handlers
├── middlewares/     # Express middleware
├── routes/         # API route definitions
├── schemas/        # Zod validation schemas
├── utils/          # Utility functions (logging)
├── app.ts          # Express app configuration
└── server.ts       # Server startup