Prerequisites:

• Before everything started. Please make sure you have installed Node.js on your system.

Through out this article, we will know more about:

• Package.json
• Install Module
  • Dev Dependency VS Regular Dependency
• Update Module
• Remove Module
• Summary

Package.json

Package.json file is the file that contains all info of your project such as it will

• listed out all the dependency (both Regular and Dev)
• It will warn us if some of the packages are deprecated
• It can easily create NPM script by entering the command npm init

Check NPM version

npm --version

Create a Package.json file

1. npm init
2. package name: (npm) : Type Your Package Name Here
3. version (1.0.0) : Normally we will skip for this
4. description : Descriptions to describe your project
5. entry point (index.js) : This is the main javascript file. Sometimes people like to name it main.js, server.js and etc
6. test command : We don’t have any test command
7. git respository : Put the respository if any
8. keywords : Put the keywords if any
9. author : Put your name as the author of this project
10. license: (ISC) : You may put the license. Usually will be MIT

If you want to create a package.json without going through all these steps, npm init -y or npm init --yes will allow you to create a NPM script with default value.
Then you should see a file created call package.json

{
  "name": "npm-testing",
  "version": "1.0.0",
  "description": "This is the demo of NPM script",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "Jeff",
  "license": "MIT"
}

Set, Get & DELETE default value

Some keys such as author and license will be quite similar all the time. This case we can then give them a default value so that it skip for asking the value when we trying to create this NPM script

SET

• npm set init-author-name < Your Name Here >
• npm set init-license < Default License >

GET

• npm get init-author-name
• npm get init-license

DELETE

• npm config delete init-author-name
• npm config delete init-license

Install Package

Note: Installed modules are added as a dependency by default, so the –save option is no longer needed.

For example:
From npm install < module name > --save to npm install < module name >

or

From npm i < module name > --save to npm i < module name >

Install with version

npm install <package>@<version> allow us to install the module with specific version.
For example, the latest version of Express is 4.16.4 but if we wanted to install the older version of this. We can enter the command
npm install express@4.16.4

Dev Dependency VS Regular Dependency

By default, if we never added the command -D isuch as npm i <module> -D command, it will be auto save in our regular dependency.
One main different between Dev Dependency VS Regular Dependency is that whatever inside the Dev Dependencies are not going to use in the production while whatever inside Regular Dependencies will be used in the production.

One good example on this is when we try to create a server in Nodejs with Express framework. Normally we will install Express in our regular dependency and install Nodemon (Update the result without restarting the server) in our dev dependency.

After you had installed the modules, there will be some changes in our package.json file which will then added dependencies and devDependencies object.

{
  "name": "npm-testing",
  "version": "1.0.0",
  "description": "This is the demo of NPM script",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "Jeff",
  "license": "MIT",
  "dependencies": {
    "express": "^4.16.4"
  },
  "devDependencies": {
    "nodemon": "^2.0.6"
  }
}

Update Module

Update Module is pretty straight forward. Let’s take the Express module as example.
npm update express will update the Express version from 4.16.4 to the latest version 4.17.1 (up to 20/12/2020)

Or the other way to update all modules to the latest version is by entering the command npx npm-update-all

Remove Module

Remove/ Uninstall module is also very straigh forward.
npm remove <module> or npm rm <module> will do the job for both regular and dev dependencies

Summary