Blog Platform Backend

A NestJS-based GraphQL backend for a blog platform with real-time notifications.

Features

• User Authentication: User registration and login with JWT tokens
• Blog Management: Create, read, update, and delete blog posts
• Real-time Notifications: GraphQL subscriptions for real-time blog notifications
• GraphQL API: Full GraphQL API with queries, mutations, and subscriptions
• PostgreSQL: Database for persistent storage
• Redis: Pub/Sub for cross-instance notifications

Architecture

Backend
├── GraphQL Gateway (Apollo Server)
├── Auth Module (JWT authentication)
├── Blog Module (CRUD operations)
└── Notification Service (Real-time subscriptions)

Infrastructure
├── PostgreSQL (Database)
└── Redis (Pub/Sub)

Prerequisites

• Node.js (v18 or higher)
• PostgreSQL (v12 or higher)
• Redis (v6 or higher)

Installation

1. Install dependencies:

npm install

2. Set up environment variables:

cp .env.example .env

Edit .env with your database and Redis configuration:

DB_HOST=localhost
DB_PORT=5432
DB_USERNAME=postgres
DB_PASSWORD=postgres
DB_NAME=rpg_blog

JWT_SECRET=your-secret-key-change-in-production

REDIS_HOST=localhost
REDIS_PORT=6379

PORT=3200
FRONTEND_URL=http://localhost:3000

3. Create PostgreSQL database:

CREATE DATABASE rpg_blog;

4. Start Redis:

redis-server

Running the Application

Development

npm run start:dev

The server will start on http://localhost:3200 and GraphQL playground will be available at http://localhost:3200/graphql.

GraphQL API

Authentication

Register User

mutation {
  register(input: {
    email: "user@example.com"
    username: "johndoe"
    password: "password123"
  }) {
    token
    user {
      id
      email
      username
    }
  }
}

Login

mutation {
  login(input: {
    email: "user@example.com"
    password: "password123"
  }) {
    token
    user {
      id
      email
      username
    }
  }
}

Blog Operations

Create Blog (Requires authentication)

mutation {
  createBlog(input: {
    title: "My First Blog Post"
    content: "This is the content of my blog post."
  }) {
    id
    title
    content
    author {
      id
      username
    }
    createdAt
  }
}

Get All Blogs

query {
  blogs {
    id
    title
    content
    author {
      id
      username
    }
    createdAt
  }
}

Get Single Blog

query {
  blog(id: "blog-id") {
    id
    title
    content
    author {
      id
      username
    }
    createdAt
  }
}

Update Blog (Requires authentication, owner only)

mutation {
  updateBlog(id: "blog-id", input: {
    title: "Updated Title"
    content: "Updated content"
  }) {
    id
    title
    content
  }
}

Delete Blog (Requires authentication, owner only)

mutation {
  deleteBlog(id: "blog-id")
}

Real-time Notifications

Subscribe to New Blog Notifications

subscription {
  newBlogNotification {
    message
    blog {
      id
      title
      content
      author {
        id
        username
      }
      createdAt
    }
    timestamp
  }
}

Authentication

For protected operations (mutations and some queries), include the JWT token in the Authorization header:

Authorization: Bearer <your-jwt-token>

For GraphQL subscriptions, pass the token in the connection parameters:

{
  authorization: `Bearer ${token}`
}

Project Structure

src/
├── auth/              # Authentication module
│   ├── entities/      # User entity
│   ├── dto/           # Data transfer objects
│   ├── guards/        # JWT guards
│   ├── strategies/    # Passport strategies
│   └── decorators/    # Custom decorators
├── blog/              # Blog module
│   ├── entities/      # Blog entity
│   └── dto/           # Blog DTOs
├── notification/      # Notification service
│   └── dto/           # Notification DTOs
├── config/            # Configuration files
└── main.ts            # Application entry point

Environment Variables

• DB_HOST: PostgreSQL host (default: localhost)
• DB_PORT: PostgreSQL port (default: 5432)
• DB_USERNAME: PostgreSQL username (default: postgres)
• DB_PASSWORD: PostgreSQL password (default: postgres)
• DB_NAME: Database name (default: rpg_blog)
• JWT_SECRET: Secret key for JWT tokens
• REDIS_HOST: Redis host (default: localhost)
• REDIS_PORT: Redis port (default: 6379)
• REDIS_PASSWORD: Redis password (optional)
• PORT: Server port (default: 3200)
• FRONTEND_URL: Frontend URL for CORS (default: http://localhost:3000)
• NODE_ENV: Environment (development/production)

Testing

# Unit tests
npm run test

# E2E tests
npm run test:e2e

# Test coverage
npm run test:cov

License

UNLICENSED