Building a REST API with Node.js and Express

In this tutorial, we'll learn how to build a robust REST API using Node.js and Express. We'll cover everything from setup to deployment.

Prerequisites

• Node.js installed on your machine
• Basic JavaScript knowledge
• Understanding of HTTP methods

Project Setup

First, let's create a new project and install the necessary dependencies:

mkdir rest-api-tutorial
cd rest-api-tutorial
npm init -y
npm install express dotenv mongoose

Creating the Server

Create a new file called server.js:

const express = require('express');
const dotenv = require('dotenv');

// Load environment variables
dotenv.config();

// Initialize express
const app = express();

// Middleware
app.use(express.json());

// Basic route
app.get('/', (req, res) => {
  res.json({ message: 'Welcome to our API!' });
});

// Start server
const PORT = process.env.PORT || 5000;
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

Adding Routes

Create a new folder called routes and add users.js:

const express = require('express');
const router = express.Router();

// Get all users
router.get('/', (req, res) => {
  res.json({ users: [] });
});

// Create new user
router.post('/', (req, res) => {
  const { name, email } = req.body;
  // Add validation here
  res.status(201).json({ message: 'User created' });
});

module.exports = router;

Error Handling

Create a middleware for handling errors:

// middleware/error.js
const errorHandler = (err, req, res, next) => {
  console.error(err.stack);

  res.status(err.status || 500).json({
    error: {
      message: err.message || 'Internal Server Error',
      status: err.status || 500
    }
  });
};

module.exports = errorHandler;

Testing the API

You can test your API using tools like Postman or curl:

# Get all users
curl http://localhost:5000/api/users

# Create a new user
curl -X POST http://localhost:5000/api/users \
  -H "Content-Type: application/json" \
  -d '{"name": "John Doe", "email": "john@example.com"}'

Best Practices

1. Always validate input data
2. Use proper HTTP status codes
3. Implement rate limiting
4. Add authentication and authorization
5. Document your API

Conclusion

You now have a basic REST API setup with Node.js and Express. This foundation can be extended with additional features like:

• Database integration
• Authentication
• File uploads
• Rate limiting
• API documentation

Remember to follow REST principles and maintain clean code structure as your API grows.