a list of awesome nodejs modules and their usages
Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.
npm install expressconst express = require('express');
const app = express();
const port = 3000;
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.listen(port, () => {
console.log(`Example app listening at http://localhost:${port}`);
});This example sets up a basic web server that responds with "Hello World!" when accessed.
Mongoose is an Object Data Modeling (ODM) library for MongoDB and Node.js, which provides a straightforward, schema-based solution to model your application data.
npm install mongooseconst mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test', { useNewUrlParser: true, useUnifiedTopology: true });
const Cat = mongoose.model('Cat', { name: String });
const kitty = new Cat({ name: 'Zildjian' });
kitty.save().then(() => console.log('meow'));This example connects to a MongoDB database and saves a simple document.
jsonwebtoken is a library to work with JSON Web Tokens (JWTs). It can be used for securely transmitting information between parties as a JSON object.
npm install jsonwebtokenconst jwt = require('jsonwebtoken');
const token = jwt.sign({ foo: 'bar' }, 'shhhhh');
console.log('Generated Token:', token);
jwt.verify(token, 'shhhhh', (err, decoded) => {
if (err) {
console.error('Token verification failed:', err);
} else {
console.log('Decoded Token:', decoded);
}
});This example generates a JWT and verifies it.
Lodash is a modern JavaScript utility library delivering modularity, performance, & extras.
npm install lodashconst _ = require('lodash');
const array = [1, 2, 3, 4, 5, 6];
const evens = _.filter(array, num => num % 2 === 0);
console.log('Even numbers:', evens);This example uses Lodash to filter an array for even numbers.
Chalk is a terminal string styling library that allows you to style your terminal output.
npm install chalkconst chalk = require('chalk');
console.log(chalk.blue('Hello world!'));
console.log(chalk.red('This text is red!'));
console.log(chalk.green('This text is green!'));This example demonstrates how to style terminal text using Chalk.
dotenv is a zero-dependency module that loads environment variables from a .env file into process.env.
npm install dotenvCreate a .env file:
DB_HOST=localhost
DB_USER=root
DB_PASS=s1mpl3
Load the environment variables in your code:
require('dotenv').config();
console.log('Database Host:', process.env.DB_HOST);
console.log('Database User:', process.env.DB_USER);
console.log('Database Password:', process.env.DB_PASS);This example shows how to load environment variables from a .env file.
Moment is a library for parsing, validating, manipulating, and formatting dates.
npm install momentconst moment = require('moment');
const now = moment();
console.log('Current date and time:', now.format('YYYY-MM-DD HH:mm:ss'));
const tomorrow = moment().add(1, 'days');
console.log('Tomorrow:', tomorrow.format('YYYY-MM-DD'));This example shows how to manipulate and format dates using Moment.
bcrypt is a library to help you hash passwords.
npm install bcryptconst bcrypt = require('bcrypt');
const saltRounds = 10;
const myPlaintextPassword = 's0/\/\P4$$w0rD';
bcrypt.hash(myPlaintextPassword, saltRounds, (err, hash) => {
if (err) {
console.error('Error hashing password:', err);
} else {
console.log('Hashed password:', hash);
bcrypt.compare(myPlaintextPassword, hash, (err, result) => {
if (err) {
console.error('Error comparing password:', err);
} else {
console.log('Password match:', result);
}
});
}
});This example demonstrates how to hash and compare passwords using bcrypt.
Absolutely! Here are some additional useful Node.js modules along with examples:
The async library provides powerful functions for working with asynchronous JavaScript, making it easier to manage complex flows.
npm install asyncconst async = require('async');
async.series([
function(callback) {
setTimeout(() => {
console.log('Task 1');
callback(null, 1);
}, 1000);
},
function(callback) {
setTimeout(() => {
console.log('Task 2');
callback(null, 2);
}, 500);
}
], (err, results) => {
console.log('Results:', results);
});This example shows how to run tasks in series.
Winston is a versatile logging library for Node.js.
npm install winstonconst winston = require('winston');
const logger = winston.createLogger({
level: 'info',
format: winston.format.json(),
transports: [
new winston.transports.Console(),
new winston.transports.File({ filename: 'combined.log' })
]
});
logger.info('Hello, this is an info message');
logger.error('Hello, this is an error message');This example demonstrates basic logging with Winston.
Multer is a middleware for handling multipart/form-data, which is primarily used for uploading files.
npm install multerconst express = require('express');
const multer = require('multer');
const upload = multer({ dest: 'uploads/' });
const app = express();
app.post('/upload', upload.single('file'), (req, res) => {
res.send('File uploaded successfully');
});
app.listen(3000, () => {
console.log('Server started on port 3000');
});This example sets up a route to handle file uploads.
Nodemailer is a module for sending emails from Node.js applications.
npm install nodemailerconst nodemailer = require('nodemailer');
let transporter = nodemailer.createTransport({
service: 'gmail',
auth: {
user: 'your-email@gmail.com',
pass: 'your-email-password'
}
});
let mailOptions = {
from: 'your-email@gmail.com',
to: 'recipient-email@example.com',
subject: 'Test Email',
text: 'Hello, this is a test email sent from Node.js'
};
transporter.sendMail(mailOptions, (error, info) => {
if (error) {
console.error('Error sending email:', error);
} else {
console.log('Email sent:', info.response);
}
});This example shows how to send an email using Nodemailer.
CORS is a middleware to enable Cross-Origin Resource Sharing in Express applications.
npm install corsconst express = require('express');
const cors = require('cors');
const app = express();
app.use(cors());
app.get('/', (req, res) => {
res.send('CORS enabled');
});
app.listen(3000, () => {
console.log('Server started on port 3000');
});This example sets up an Express server with CORS enabled.
Helmet helps secure Express apps by setting various HTTP headers.
npm install helmetconst express = require('express');
const helmet = require('helmet');
const app = express();
app.use(helmet());
app.get('/', (req, res) => {
res.send('Helmet security headers enabled');
});
app.listen(3000, () => {
console.log('Server started on port 3000');
});This example demonstrates how to enhance security using Helmet.
PM2 is a production process manager for Node.js applications that allows you to keep applications alive forever, reload them without downtime, and facilitate common system admin tasks.
npm install pm2 -gpm2 start app.js
pm2 list
pm2 stop app.js
pm2 restart app.js
pm2 delete app.jsThis example shows basic commands for managing a Node.js application with PM2.
Compression middleware for compressing HTTP responses in Express.
npm install compressionconst express = require('express');
const compression = require('compression');
const app = express();
app.use(compression());
app.get('/', (req, res) => {
res.send('Hello, compressed world!');
});
app.listen(3000, () => {
console.log('Server started on port 3000');
});This example shows how to enable response compression in an Express app.
Socket.IO enables real-time, bidirectional, and event-based communication.
npm install socket.ioconst express = require('express');
const http = require('http');
const socketIo = require('socket.io');
const app = express();
const server = http.createServer(app);
const io = socketIo(server);
io.on('connection', (socket) => {
console.log('A user connected');
socket.on('disconnect', () => {
console.log('User disconnected');
});
});
server.listen(3000, () => {
console.log('Server started on port 3000');
});This example sets up a basic Socket.IO server.
Sequelize is a promise-based Node.js ORM for Postgres, MySQL, MariaDB, SQLite, and Microsoft SQL Server.
npm install sequelize
npm install pg pg-hstore # for PostgreSQLconst { Sequelize, DataTypes } = require('sequelize');
const sequelize = new Sequelize('database', 'username', 'password', {
host: 'localhost',
dialect: 'postgres'
});
const User = sequelize.define('User', {
username: {
type: DataTypes.STRING,
allowNull: false
},
birthday: {
type: DataTypes.DATE,
allowNull: false
}
});
sequelize.sync()
.then(() => User.create({
username: 'john_doe',
birthday: new Date(1990, 1, 1)
}))
.then(user => {
console.log('User created:', user.toJSON());
});This example demonstrates how to define a model and interact with a PostgreSQL database using Sequelize.