Test PR - NestJS Application

This is a test project demonstrating NestJS with PostgreSQL, GraphQL, and RabbitMQ integration.

Description

A comprehensive NestJS application featuring REST API, GraphQL API, database integration with TypeORM, and asynchronous task processing with RabbitMQ.

Features

• NestJS Framework with TypeScript
• PostgreSQL database integration with TypeORM
• GraphQL API with Apollo Server
• REST API endpoints
• RabbitMQ Integration for task queue processing
• User Management System with CRUD operations
• Task Queue System with producer/consumer pattern
• Environment Configuration
• Code Quality Tools (ESLint, Prettier)

Installation

pnpm install

Environment Configuration

Copy the example environment file and configure your settings:

cp .env.example .env

Configure the following environment variables:

# Database Configuration
DB_HOST=localhost
DB_PORT=5432
DB_USERNAME=postgres
DB_PASSWORD=postgres
DB_DATABASE=test_db

# RabbitMQ Configuration
RABBITMQ_URL=amqp://localhost:5672

Prerequisites

PostgreSQL Setup

Make sure you have PostgreSQL running and create a database:

CREATE DATABASE test_db;

RabbitMQ Setup

Install and start RabbitMQ server:

# Docker
docker run -it --rm --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:4-management

RabbitMQ Management UI will be available at: http://localhost:15672 (guest/guest)

Running the app

# development with hot reload
pnpm run start:dev

# development
pnpm run start

# production mode
pnpm run start:prod

API Endpoints

REST API

• GET / - Hello World endpoint
• GET /users - Get all users
• POST /users - Create a new user
• POST /tasks - Create a new task (publishes to RabbitMQ queue)

GraphQL API

• Endpoint: /graphql
• Playground available at: http://localhost:3000/graphql

RabbitMQ Task Queue

Tasks created via POST /tasks are automatically:

1. Published to task_exchange with routing key task.create
2. Consumed from task_queue by the consumer
3. Processed by printing task details to console

Sample Requests

Use the requests.http file to test all API endpoints including RabbitMQ task examples:

• User management (REST & GraphQL)
• Task creation and queue processing
• Various request patterns

Testing

# unit tests
pnpm run test

# watch mode
pnpm run test:watch

# e2e tests
pnpm run test:e2e

# test coverage
pnpm run test:cov

Code Quality

# run linter with auto-fix
pnpm run lint

# format code
pnpm run format

# build project
pnpm run build

Tech Stack

• Framework: NestJS
• Language: TypeScript
• Database: PostgreSQL
• ORM: TypeORM
• GraphQL: Apollo Server
• Message Queue: RabbitMQ (@golevelup/nestjs-rabbitmq)
• Package Manager: pnpm
• Code Quality: ESLint, Prettier
• Testing: Jest, Supertest

Project Structure

src/
├── app.controller.ts       # Main application controller
├── app.module.ts           # Root application module
├── app.service.ts          # Main application service
├── main.ts                 # Application entry point
├── tasks/                  # Task queue module
│   ├── create-task.dto.ts  # Task data transfer objects
│   ├── tasks.controller.ts # Task REST endpoints
│   ├── tasks.consumer.ts   # RabbitMQ message consumer
│   ├── tasks.module.ts     # Task module configuration
│   └── tasks.service.ts    # Task producer service
└── users/                  # User management module
    ├── dto/
    │   └── create-user.input.ts
    ├── user.entity.ts
    ├── users.controller.ts
    ├── users.module.ts
    ├── users.resolver.ts
    └── users.service.ts

RabbitMQ Architecture

The application implements a Producer/Consumer pattern:

Producer Flow

1. Client sends POST /tasks with task data
2. TasksService creates task with unique ID and timestamp
3. Task is published to task_exchange with routing key task.create
4. Response is returned to client immediately

Consumer Flow

1. TasksConsumer listens to task_queue
2. When task is received, it processes by logging task details
3. Task is automatically acknowledged after successful processing

Queue Configuration

• Exchange: task_exchange (topic)
• Queue: task_queue
• Routing Key: task.create

Development Guidelines

• Follow existing code style and patterns
• Use TypeScript strict mode
• Write tests for new features
• Use meaningful commit messages
• Update documentation when adding new features
• Ensure RabbitMQ is running for full functionality

Monitoring

• Application: http://localhost:3000
• GraphQL Playground: http://localhost:3000/graphql
• RabbitMQ Management: http://localhost:15672 (guest/guest)

License

This project is licensed under the UNLICENSED license.