Creating a server using npm init

  
  └─$ npm init              
  This utility will walk you through creating a package.json file.
  It only covers the most common items, and tries to guess sensible defaults.

  See 'npm help init' for definitive documentation on these fields
  and exactly what they do.

  Use 'npm install <pkg>' afterwards to install a package and
  save it as a dependency in the package.json file.

  Press ^C at any time to quit.
  package name: (folder_name_here) _
                

It means it will ask you to write every field inside terminal. After completing the steps, it should looks like:

  
  ┌──(niraj㉿kali)-[~/Desktop/js/nodejs/blog-mern-yt]
  └─$ npm init              
  This utility will walk you through creating a package.json file.
  It only covers the most common items, and tries to guess sensible defaults.

  See "npm help init" for definitive documentation on these fields
  and exactly what they do.

  Use "npm install <pkg>" afterwards to install a package and
  save it as a dependency in the package.json file.

  Press ^C at any time to quit.
  package name: (blog-mern-yt) 
  version: (1.0.0) 
  description: backend app for mern blog app
  entry point: (index.js) 
  test command: 
  git repository: 
  keywords: backend mern blog-app
  author: Niraj Chaurasiya
  license: (ISC) 
  About to write to /home/niraj/Desktop/js/nodejs/blog-mern-yt/package.json:

  {
    "name": "blog-mern-yt",
    "version": "1.0.0",
    "description": "backend app for mern blog app",
    "main": "index.js",
    "scripts": {
      "test": "echo "Error: no test specified" && exit 1"
    },
    "keywords": [
      "backend",
      "mern",
      "blog-app"
    ],
    "author": "Niraj Chaurasiya",
    "license": "ISC"
  }


  Is this OK? (yes) 

  ┌──(niraj㉿kali)-[~/Desktop/js/nodejs/blog-mern-yt]
  └─$ 
                

When it prompts above, it means a package.json file has been created inside the root foleder of the current directory.

A package.json file looks something like:

  
  {
    "name": "blog-mern-yt",
    "version": "1.0.0",
    "description": "backend app for mern blog app",
    "main": "index.js",
    "scripts": {
      "test": "echo "Error: no test specified" && exit 1"
    },
    "keywords": [
      "backend",
      "mern",
      "blog-app"
    ],
    "author": "Niraj Chaurasiya",
    "license": "ISC"
  }
                

Now, lets initialize it by adding -y at last.

  
 ┌──(niraj㉿kali)-[~/Desktop/js/nodejs/blog-mern-yt]
 └─$ npm init -y
  Wrote to /home/niraj/Desktop/js/nodejs/blog-mern-yt/package.json:

  {
    "name": "blog-mern-yt",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
      "test": "echo "Error: no test specified" && exit 1"
    },
    "keywords": [],
    "author": "",
    "license": "ISC"
  }

  ┌──(niraj㉿kali)-[~/Desktop/js/nodejs/blog-mern-yt]
  └─$ 
  

Now, our package.json looks like:

  
  {
    "name": "blog-mern-yt",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
      "test": "echo "Error: no test specified" && exit 1"
    },
    "keywords": [],
    "author": "",
    "license": "ISC"
  }
  

In both the cases, it creates a package.json file but one with default value and the other with user entered value.

So, this is the main difference in creating a package.json file with and without -y at last.

Now, that we have successfully created a package.json file, lets create a basic backend server.

Inside the same folder, create an index.js file as written inside the package.json as main file.

  
  Root folder
  --- index.js
  --- package.json
  

We are going to make the server with ExpressJS.

In case you don't know ExpressJS, it is a JS library that helps to create servers with NodeJS

For more info: ExpressJS Official website

Now, install express and nodemon using npm install express nodemon by using terminal.

Open index.js file and write the following module code!

  
  import express from "express";

  const PORT = 8000;
  const app = express();

  app.listen(PORT, () => {
    console.log("Backend running on + ", PORT);
  });
  

Now, open package.json and modify it.

  
  {
    "name": "backend",
    "version": "1.0.0",
    "description": "Backend for blog app",
    "main": "app.js",
    "type": "module",
    "scripts": {
      "start": "nodemon index.js" // changes here
    },
    "keywords": [],
    "author": "Niraj Chaurasiya",
    "license": "ISC",
    "dependencies": {
      "dotenv": "^16.4.5",
      "express": "^4.19.2",
      "nodemon": "^3.1.4"      
    },
    "devDependencies": {
      "@types/express": "^4.17.21"
    }
  }
  

After making all the changes, run npm start.

It should show:

  
  ┌──(niraj㉿kali)-[~/Desktop/js/nodejs/blog-mern-yt]
  └─$ npm start    

  > blog-mern-yt@1.0.0 start
  > nodemon index.js

  [nodemon] 3.1.4
  [nodemon] to restart at any time, enter "rs"
  [nodemon] watching path(s): *.*
  [nodemon] watching extensions: js,mjs,cjs,json
  [nodemon] starting node index.js
  Backend running on 8000
  

Now, we have successfully created a basic backend server with Express!

Open, http://localhost:8000, and you should see, cannot get /