Interview Quiz Application - Backend

MySQL + Express + Node.js Backend API

Project Structure

backend/
├── config/          # Configuration files (database, etc.)
├── controllers/     # Request handlers
├── middleware/      # Custom middleware (auth, validation, etc.)
├── models/          # Sequelize models
├── routes/          # API route definitions
├── migrations/      # Database migrations
├── seeders/         # Database seeders
├── tests/           # Test files
├── server.js        # Main application entry point
├── .env             # Environment variables (not in git)
├── .env.example     # Environment variables template
└── package.json     # Dependencies and scripts

Prerequisites

• Node.js 18+
• MySQL 8.0+
• npm or yarn

Installation

1. Navigate to backend directory:

   cd backend
   

2. Install dependencies:

   npm install
   

3. Setup environment variables:

   cp .env.example .env
   

   Then edit .env with your database credentials.

4. Create MySQL database:

   CREATE DATABASE interview_quiz_db CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
   

Running the Application

Development Mode

npm run dev

Uses nodemon for auto-restart on file changes.

Production Mode

npm start

Server will start on:

• URL: http://localhost:3000
• API Endpoint: http://localhost:3000/api
• Health Check: http://localhost:3000/health

Database Management

Initialize Sequelize

npx sequelize-cli init

Run Migrations

npm run migrate

Undo Last Migration

npm run migrate:undo

Run Seeders

npm run seed

Undo Seeders

npm run seed:undo

Testing

Run all tests

npm test

Run tests in watch mode

npm run test:watch

API Endpoints

Coming soon... (Will be documented as features are implemented)

Authentication

• POST /api/auth/register - Register new user
• POST /api/auth/login - Login user
• POST /api/auth/logout - Logout user
• GET /api/auth/verify - Verify JWT token

Categories

• GET /api/categories - Get all categories
• GET /api/categories/:id - Get category by ID

Questions

• GET /api/questions/category/:categoryId - Get questions by category
• GET /api/questions/:id - Get question by ID
• GET /api/questions/search - Search questions

Quiz

• POST /api/quiz/start - Start quiz session
• POST /api/quiz/submit - Submit answer
• POST /api/quiz/complete - Complete quiz session
• GET /api/quiz/session/:sessionId - Get session details

User Dashboard

• GET /api/users/:userId/dashboard - Get user dashboard
• GET /api/users/:userId/history - Get quiz history
• PUT /api/users/:userId - Update user profile

Admin

• GET /api/admin/statistics - Get system statistics
• GET /api/admin/guest-settings - Get guest settings
• PUT /api/admin/guest-settings - Update guest settings

Environment Variables

Variable	Description	Default
NODE_ENV	Environment (development/production)	development
PORT	Server port	3000
API_PREFIX	API route prefix	/api
DB_HOST	MySQL host	localhost
DB_PORT	MySQL port	3306
DB_NAME	Database name	interview_quiz_db
DB_USER	Database user	root
DB_PASSWORD	Database password	-
JWT_SECRET	Secret key for JWT tokens	-
JWT_EXPIRE	JWT expiration time	24h
CORS_ORIGIN	Allowed CORS origin	http://localhost:4200

Development Workflow

1. Create a feature branch

   git checkout -b feature/your-feature-name
   

2. Implement your feature

   • Follow the tasks in BACKEND_TASKS.md
   • Write tests for your code
   • Update this README if needed

3. Test your changes

   npm test
   

4. Commit and push

   git add .
   git commit -m "feat: your feature description"
   git push origin feature/your-feature-name
   

Technologies Used

• Express.js - Web framework
• Sequelize - ORM for MySQL
• MySQL2 - MySQL driver
• JWT - Authentication
• Bcrypt - Password hashing
• Helmet - Security headers
• CORS - Cross-origin resource sharing
• Morgan - HTTP request logger
• Express Validator - Input validation
• Express Rate Limit - Rate limiting
• Jest - Testing framework
• Supertest - API testing

Testing Database Connection

To test the database connection:

npm run test:db

This will verify:

• MySQL server is running
• Database credentials are correct
• Database exists
• Connection is successful

Environment Configuration

All environment variables are validated on server startup. To manually validate:

npm run validate:env

To generate a new JWT secret:

npm run generate:jwt

See ENVIRONMENT_GUIDE.md for complete configuration documentation.

Testing Models

To test the User model:

npm run test:user

This verifies:

• User creation with UUID
• Password hashing
• Password comparison
• Validation rules
• Helper methods

Next Steps

Follow the tasks in BACKEND_TASKS.md:

• ✅ Task 1: Project Initialization (COMPLETED)
• ✅ Task 2: Database Setup (COMPLETED)
• ✅ Task 3: Environment Configuration (COMPLETED)
• ✅ Task 4: Create User Model & Migration (COMPLETED)
• 🔄 Task 5: Create Categories Model & Migration (NEXT)
• ... and more

Documentation References

• BACKEND_TASKS.md - Complete task list
• SEQUELIZE_QUICK_REFERENCE.md - Code examples
• SAMPLE_MIGRATIONS.md - Migration templates
• interview_quiz_user_story.md - Full specification

License

ISC