Starter Template

Check Node

Node.js Use for execute JavaScript

Verify Installation

node --version // This should display the installed Node.js version.

Project Initialization

npm init

This will ask several questions (like project name, version, description, entry point, etc.). You can press Enter to accept the defaults or provide your own values.

Quick Initialization

npm init -y

This generates a package.json file with default settings.

Version Format

version Format → Three dot format → 1.0.0
Called → Semantic Versioning (**SemVer)**

Semantic Versioning

Semantic Versioning (SemVer) is a versioning scheme for software that follows the format.

MAJOR.MINOR.PATCH

MAJOR → Increases when you make incompatible API changes.
MINOR → Increases when you add backward-compatible new features.
PATCH → Increases when you make backward-compatible bug fixes.

Example:
1.0.0 → Initial stable release.
1.1.0 → Added a new feature (backward compatible).
1.1.1 → Fixed a bug (backward compatible).
2.0.0 → Introduced breaking changes.

After running `npm init` → `package.json` file is created.

{
  "name": "full-stack-template",
  "version": "1.0.0",
  "description": "template",
  "main": "index.js",
  "scripts": {
    "test": "echo \\"Error: no test specified\\" && exit 1"
  },
  "keywords": [
    "sandeepatel"
  ],
  "author": "",
  "license": "ISC"
}

Create entry point

index.js

console.log("Hello World");

Import third-party libraries using different methods

CommonJS (CJS) → require()

// This is the default module system in Node.js
const express = require('express'); // Importing Express.js
const app = express();

ES Modules (ESM) – import

// This is the modern way to import modules in JavaScript.
import express from 'express'; // Importing Express.js
const app = express();

Used when "type": "module" is set in package.json.

Environment variables - Project Kundalee

A .env file is used to store environment variables in a key-value format.
They are useful for keeping sensitive data (e.g., API keys, database credentials) secure and making applications more flexible across different environments (development, testing, production).
Do Not Commit .env Files – Add them to .gitignore.
Use .env.sample – Share expected variables without actual values.

Install

npm install dotenv

Create a .env file

// **.env.sample**

PORT=5000
DATABASE_URL=mongodb://localhost:27017/mydb

Client-Server Communication

The client (browser or frontend app) sends requests to the server using HTTP methods (GET, POST, PUT, DELETE).
The server (Node.js with Express.js) processes the request and sends a response.

Client-Server Communication in `Node.js` using `Express.js`

Express.js is a lightweight and fast **web framework for Node.js** that helps in building APIs and web applications.

Install Express.js

npm install express

Setup a basic Express server

index.js

import express from "express";

const app = express();
const port = 3000;

app.get("/", (req, res) => {
  res.send("Cohort!");
});

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
})

Run index.js

node index.js

Sending GET Request

In Browser → http://127.0.0.1:3000/

Speed Run

Syntax

app.get("/defineRoute", Callback)

Route always start with /

import express from "express";

const app = express();
const port = 3000;

// Run on Request
app.get("/", (req, res) => {
  res.send("Cohort!");
});

app.get("/sandeep", (req, res) => {
  console.log("Sandeep!");
});

app.get("/sandy", (req, res) => {
  console.log("Sandy!");
})

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
})

Restart index.js
In Browser → http://127.0.0.1:3000/sandeep
In Browser → http://127.0.0.1:3000/sandy

Automatically restarting the server

nodemon is a tool that helps develop Node.js applications by automatically restarting the server when file changes are detected.

Installation → devDependencies

npm install -D nodemon

Edit package.json

Change scripts

{
  "name": "full-stack-template",
  "version": "1.0.0",
  "description": "template",
  "main": "index.js",
  "type": "module",
  "scripts": {
    "start": "nodemon index.js"
  },
  "keywords": [
    "sandeepatel"
  ],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "express": "^4.21.2"
  },
  "devDependencies": {
    "nodemon": "^3.1.9"
  }
}

npm run start

PORT Define

For better management, use a .env file.

.env

Install npm i dotenv
dotenv Import in index.js

import express from "express";
import dotenv from "dotenv";

dotenv.config();

const app = express();
const port = process.env.PORT || 4000;

// Run on Request
app.get("/", (req, res) => {
  res.send("Cohort!");
});

app.get("/sandeep", (req, res) => {
  res.send("Sandeep!");
});

app.get("/sandy", (req, res) => {
  res.send("Sandy!");
})

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
})

This imports the dotenv package, which is responsible for reading .env files
dotenv.config(); → This function reads the .env file and loads the variables into process.env.

CORS

CORS → Cross-Origin Resource Sharing

CORS Error resolve in Backend side.

CORS is a security feature implemented by web browsers to control how web pages can request resources from a different origin (domain, protocol, or port).

Package Installation

npm i cors

`cors` Import in `index.js`

import express from "express";
import dotenv from "dotenv";
import cors from "cors";

dotenv.config();

const app = express();
app.use(cors({
  origin: "<http://localhost:3000>", // Sirf yeh origin allow hoga
  methods: ["GET", "POST", "PUT", "DELETE"],  // Sirf inhi methods ki permission
  allowedHeaders: ["Content-Type", "Authorization"], // Sirf inhi headers ki permission
  credentials: true // Agar cookies ya authentication headers use ho rahe hain
}));

app.use(express.json()); // Body parser

const port = process.env.PORT || 4000;

// Run on Request
app.get("/", (req, res) => {
  res.send("Cohort!");
});

app.get("/sandeep", (req, res) => {
  res.send("Sandeep!");
});

app.get("/sandy", (req, res) => {
  res.send("Sandy!");
})

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
})

app.use(express.json()); → When a client (frontend or API consumer) sends a request with a JSON body, Express does not automatically parse it. You need to explicitly tell Express to parse JSON data using express.json().
app**.**use(express**.**urlencoded({ extended**:** true }))**; →** When a user submits a form using the POST method, the data is sent in application/x-www-form-urlencoded format. Express does not parse this data automatically, so we need to use express.urlencoded().

Check

In Browser → http://localhost:3000/sandy
In Browser → http://127.0.0.1:3000/sandy

Database Connection

Use Database for Saving Data
Backend → mongoose → Database

`mongoose`

Mongoose is an ODM (Object Data Modeling) library for MongoDB and Node.js.
Schema-Based Models
Built-in Validation

Installation

npm install mongoose

Connecting to MongoDB

Create /utils/db.js
Create Account in Mongodb Atlas and Create Mongodb_URL
Saved Mongodb_URL in .env

PORT=3000
MONGO_URL=

BASE_URL=http://127.0.0.1:3000

/utils/db.js

import mongoose from "mongoose";

const connectDB = async () => {
  try {
    await mongoose.connect(process.env.MONGO_URI);
    console.log(`MongoDB Connected`);
  } catch (error) {
    console.log("MongoDB Error", error);
  }
};

export default connectDB;

index.js

import express from "express";
import dotenv from "dotenv";
import cors from "cors";
import connectDB from "./utils/db.js";

dotenv.config();

const app = express();
app.use(cors({
  origin: process.env.BASE_URL, // Sirf yeh origin allow hoga
  methods: ["GET", "POST", "PUT", "DELETE"],  // Sirf inhi methods ki permission
  allowedHeaders: ["Content-Type", "Authorization"], // Sirf inhi headers ki permission
  credentials: true // Agar cookies ya authentication headers use ho rahe hain
}));

app.use(express.json()); // Body parser
app.use(express.urlencoded({ extended: true }));

const port = process.env.PORT || 4000;

// Run on Request
app.get("/", (req, res) => {
  res.send("Cohort!");
});

app.get("/sandeep", (req, res) => {
  res.send("Sandeep!");
});

app.get("/sandy", (req, res) => {
  res.send("Sandy!");
})

// Connect to DB
connectDB();

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
})

Data Modeling

Create /mode/User.mode.js Standard Structure
Common Template

import mongoose from "mongoose";

const userSchema = new mongoose.Schema()

const User = mongoose.model("User", userSchema); 
export default User;

User Schema

import mongoose from "mongoose";

const userSchema = new mongoose.Schema({
  name: String,
  email: String,
  password: String,
  role: {
    enum: ["user", "admin"],
    default: "user"
  },
  isverified: {
    type: Boolean,
    default: false
  },
  verificationToken: {
    type: String
  },
  resetPasswordToken: {
    type: String
  },
  resetPasswordExpire: {
    type: Date
  }
}, { timestamps: true });

const User = mongoose.model("User", userSchema);

export default User;

Create a separate Route file

/routes/user.routes.js

Syntax

import express from "express";

const router = express.Router();

export default router;

import express from "express";
import { registerUser } from "../controller/user.controller";

const router = express.Router();

router.get("/register", registerUser);

export default router;

// <http://127.0.0.1:3000/api/v1/users/register>

Create a separate Controller file

/controller/user.controller.js

const registerUser = async (req, res) => {
  res.send("Register User") // Bussiness Logic
}

export { registerUser };

Final index.js

import express from "express";
import dotenv from "dotenv";
import cors from "cors";
import connectDB from "./utils/db.js";

// Import All routes
import userRoutes from "./routes/user.routes.js";

dotenv.config();

const app = express();
app.use(cors({
  origin: process.env.BASE_URL, // Sirf yeh origin allow hoga
  methods: ["GET", "POST", "PUT", "DELETE"],  // Sirf inhi methods ki permission
  allowedHeaders: ["Content-Type", "Authorization"], // Sirf inhi headers ki permission
  credentials: true // Agar cookies ya authentication headers use ho rahe hain
}));

app.use(express.json()); // Body parser
app.use(express.urlencoded({ extended: true }));

const port = process.env.PORT || 4000;

// Run on Request
app.get("/", (req, res) => {
  res.send("Cohort!");
});

app.get("/sandeep", (req, res) => {
  res.send("Sandeep!");
});

app.get("/sandy", (req, res) => {
  res.send("Sandy!");
})

// Connect to DB
connectDB();

// Use Routes
app.use("/api/v1/users", userRoutes);

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
})

Backend Starter Template

Check Node

Project Initialization

Version Format

Semantic Versioning

After running `npm init` → `package.json` file is created.

Create entry point

Import third-party libraries using different methods

Environment variables - Project Kundalee

Client-Server Communication

Client-Server Communication in `Node.js` using `Express.js`

Setup a basic Express server

Sending GET Request

Speed Run

Automatically restarting the server

PORT Define

CORS

Package Installation

`cors` Import in `index.js`

Database Connection

`mongoose`

Connecting to MongoDB

Data Modeling

User Schema

Create a separate Route file

Create a separate Controller file

Comments

Welcome to Sandeep'blogs

Master Prompt Engineering With Indian Mom Dialogue

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Command Palette

Check Node

Project Initialization

Version Format

Semantic Versioning

After running npm init → package.json file is created.

Create entry point

Import third-party libraries using different methods

Environment variables - Project Kundalee

Client-Server Communication

Client-Server Communication in Node.js using Express.js

Setup a basic Express server

Sending GET Request

Speed Run

Automatically restarting the server

PORT Define

CORS

Package Installation

cors Import in index.js

Database Connection

mongoose

Connecting to MongoDB

Data Modeling

User Schema

Create a separate Route file

Create a separate Controller file

Comments

Welcome to Sandeep'blogs

Master Prompt Engineering With Indian Mom Dialogue

More from this blog

After running `npm init` → `package.json` file is created.

Client-Server Communication in `Node.js` using `Express.js`

`cors` Import in `index.js`

`mongoose`