Introduction to Node.js

Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. Unlike traditional web development paradigms where JavaScript is run on the client side, Node.js allows developers to write server-side applications in JavaScript. This unification of the development stack is a powerful concept, making it easier for developers to work on front-end and back-end code.

Key Features of Node.js

1. Asynchronous and Event-Driven: Node.js is designed to be non-blocking, which means it can accommodate multiple requests without holding up the execution of other code. This is ideal for I/O-heavy applications.
   Example: Using fs.readFile() to read files without blocking event loop.

   const fs = require('fs');
   
   fs.readFile('example.txt', (err, data) => {
       if (err) throw err;
       console.log(data.toString());
   });

2. Single-Threaded: Node.js operates on a single-threaded model with event looping, making it lightweight and efficient for handling many connections simultaneously.

3. NPM (Node Package Manager): NPM is the largest software registry that allows developers to manage dependencies in their applications easily.

Introduction to MongoDB

MongoDB is a NoSQL database that uses a flexible, JSON-like document data model to store data. Unlike SQL databases, which are based on structured tables, MongoDB allows for unstructured data storage, making it a popular choice for modern web applications.

Key Features of MongoDB

1. Schema-less Design: Each document can have a different structure, which allows for greater flexibility in data modeling.

2. Rich Query Language: MongoDB provides a powerful query language that supports a wide range of operations, including filtering, sorting, and aggregation.

3. Horizontal Scalability: MongoDB can be easily scaled across many servers, making it suitable for applications with high traffic.

Basic CRUD Operations in MongoDB

Here’s a quick look at how to perform basic CRUD operations using MongoDB’s Node.js driver.

const { MongoClient } = require('mongodb');

async function main() {
    const client = new MongoClient('mongodb://localhost:27017');

    try {
        await client.connect();
        const database = client.db('testdb');
        const collection = database.collection('users');

        // Create
        const user = { name: 'Alice', age: 25 };
        await collection.insertOne(user);

        // Read
        const query = { name: 'Alice' };
        const user = await collection.findOne(query);
        console.log(user);

        // Update
        await collection.updateOne(query, { $set: { age: 26 } });

        // Delete
        await collection.deleteOne(query);
    } finally {
        await client.close();
    }
}

main().catch(console.error);

Introduction to TypeScript

TypeScript is a superset of JavaScript that adds static types. It helps developers catch errors during development and provides better tooling, such as autocompletion and interface definitions. For a project with Node.js, using TypeScript can enhance maintainability and enforce consistent data structures.

Key Features of TypeScript

1. Static Typing: Helps catch errors early through type annotations. Developers can define types for variables, function parameters, and return values.

2. Interfaces and Enums: Allows developers to define structured types and enumerated values, creating more predictable code.

3. Compatibility: TypeScript is fully compatible with JavaScript. Any valid JavaScript code is also valid TypeScript code.

Setting Up TypeScript in a Node.js Project

To start using TypeScript with Node.js, you’ll need to install it and initialize your project:

1. Install TypeScript and ts-node:

   npm install typescript ts-node @types/node --save-dev

2. Initialize a TypeScript configuration file:

   npx tsc --init

3. Create a TypeScript file (e.g., app.ts):

   interface User {
       name: string;
       age: number;
   }
   
   const greetUser = (user: User): string => {
       return `Hello, ${user.name}!`;
   };
   
   const user: User = { name: "Alice", age: 25 };
   console.log(greetUser(user));

4. Compile and run your TypeScript file:

   npx ts-node app.ts