NPM stands for Node Package Manager. NPM is a package manager for Node/JavaScript packages or modules. It is the largest ecosystem of code/packages in the open-source code community. It helps to automate installations and updations of dependent packages/modules/dependencies.
Hi All, I'm Dinanath Jayaswal, Senior UI/Web Developer and Adobe Certified Expert Professional, I wanna welcome you to NPM - Node Package Manager - Mastering the basics tutorial for all.
This is a comprehensive & concise tutorial to learn/use the NPM - Node Package Manager. This complete & compact guide explains everything you want to know/learn about the NPM - Node Package Manager. This module will learn basics to advanced NPM commands which helps to manage application dependencies with package.json file.
NPM makes it easy for javascript developers to publish, share and reuse codes, and also makes it easy to update the codes with NPM Registry.
This Node-NPM Tutorial will help/ease in understanding the basic building, needs and fundamentals of NPM and ultimately give a head start in Nodejs.
This Course/Tutorial is ideal for:
- Candidates/Professionals who want to learn and master the basics of NPM commands
- JavaScript developers who want to know how to properly use NPM - Node Package Manager
- JavaScript/Node lovers want to acquire knowledge of NPM
- Professionals desire to become NPM Expert by publishing their own NPM modules/packages for other developers
- Developers who know JavaScript and wants to dive deeper with upcoming Node/NPM features
- Any Web designer/developer interested in getting a deep understanding of NPM - Node Package Manager
- Anyone with a passionate mindset to learn new/latest/upcoming tools/technologies/concepts/web standards to sharpen/improve their skills
After completing/attending/finishing this Course/Tutorial, participants should be able to:
- Understand What-Why of Node, NPM, also how to use
- Get a strong understanding of various npm commands and be able to make use of npm for Node, Angular, React and other similar technologies
- Initialize and Setup new project/app using
npm init - Understand the purpose of
package.jsonandpackage-lock.jsonfile - Work with project dependencies and development dependencies (manage, list, update, remove dependencies as per requirement)
- Discover the Semantic versioning system (Semver)
- Configure NPM scripts and execute them
- Publish, update own solutions/package/modules to the npm registry
- Basic/Intermediate knowledge of HTML5 and CSS3
- Basics of JavaScript will be an added advantage
- How to use a text editor such as Notepad++, Sublime Text and/or IDE like Visual Studio Code
- How to use Command Line Tool, Terminal, Command Prompt to type a basic commands
-
- 1.1. What is Node-Nodejs
- 1.2. Why Node
- 1.3. What Node can do?
- 1.4. Installing Node/NPM
-
- 2.1. What is NPM
- 2.2. Package Manager/Module Manager | Package Management System
- 2.2.1. Package-Module
- 2.2.2. Package Management System
- 2.2.3. Dependencies
- 2.3. NPM Role-functionality
- 2.4. Advantages of NPM
-
- 3.1. Installing NPM
- 3.2. NPM Help | Getting NPM Help
- 3.3. Package json init
- 3.3.1. package json
- 3.3.2. package-lock json
- 3.3.3. package json benefits
- 3.3.4. Basic-Common Project File Folder Structure-Architecture
- 3.4. SemVer | Semantic Versioning | Semantic Versioning System
- 3.5. package json Defaults | package json Default values
-
Installation of the NPM packages | Dealing with NPM packages NPM Registry
- 4.1. Popular famous NPM Packages
- 4.2. More on NPM Packages | Local and Global Packages
- 4.3. Installing Local Packages | Installing Node-NPM Package Locally
- 4.3.1. Installing Specific Version of a Package
- 4.4. Uninstalling Local Packages
- 4.5. Installing Global Packages
- 4.6. Uninstalling Global Packages
- 4.7. Listing the Installed Packages
- 4.8. Installing from package json | Using readymade package json
- 4.9. Updating Packages
- 4.9.1. NPM Outdated
- 4.9.2. Updating Local Packages
- 4.9.3. Updating Global Packages
- 4.9.4. Updating Saving Dependencies
- 4.9.5. Updating Latest Major release
- 4.10. NPM Prune | Remove Unused Extraneous Packages
- 4.11. Viewing Registry Info for a Package | Package Metadata Details Info
-
Using a Extermal Package | Using a Extermal Third Party Package
-
Package Dependencies | Package Dependency Management
- 6.1. Application Dependencies
- 6.2. Dev Dependencies
- Node is a cross-platform, open-source runtime environment for executing JavaScript outside the browser i.e. at the server. We often use Node to build back-end services ie. API (Application Programming Interface)
- Node is ideally used to build Highly-scalable, data-intensive, real-time back-end services bases applications
- Nodejs is one of the most powerful and popular server technology. Google Chrome's V8 JavaScript engine is the core of Nodejs
- Node/Nodejs is open source server environment, it uses JavaScript on server
- Nodejs is a JavaScript runtime/code built on Google Chromes V8 javascript runtime engine. The V8 engine is written in C++ language which takes node(javascript) code and quickly compile/convert to machine code
- Nodejs can be defined/described with the following important terms:
- Asynchronous
- Non-blocking
- Event-Based
- Single thread / Single-threaded
- Great for prototyping and agile development
- Super-fast and highly scalable
- Non-blocking - Asynchronous nature (more tasks/code run at a time)
- JavaScript is a programming language used everywhere (Front-end + Back-end)
- Cleaner and more consistent codebase/source code
- The largest ecosystem of open-source libraries
- Great open-source community support
Node/Nodejs can perform/do the following important things:
- Generate Dynamic page content
- Can Create, Open, Read, Write, Delete files on the server
- Collect Form Data
- Can perform CRUD (Create-Add, Read, Update-Edit/Modify, Delete) operation in Database
In this section, we will learn how to set up a local development environment by installing Node/NPM:
- NPM bundled and shift with Nodejs. In order to have NPM on our machine, we just need to download and install Node
- NPM is pre-built with Node/Nodejs so it gets installed automatically - no need to install it separately
- To verify node/npm available/installed on machine, type command:
node -v/node --versionnpm -v/npm --version
- If Node not available on machine than download and Install latest nodejs installer as per your OS, and continue installation (website: https://nodejs.org/en)
- One can install LTS (Long Term Support) verion or current latest version anything is fine
- After installation, check installed version of node and npm or verify installation by using command:
- To get/check version of node, command:
node -v/node --versionOR - To get/check version of npm, command:
npm -v/npm --version
- To get/check version of node, command:
- NPM stands for
Node Package Manager - It is responsible for managing all the Node.js packages/dependencies and modules present in an application
- NPM comes
bundled with Node/Nodejs, so it gets installed directly/automatically with Node - NPM is the default package manager for Node, and it's fully written/coded/developed in JavaScript
NPM (Node Package Manager)is a command-line tool and registry for Third-Party Library(s) which we can add to our Node/Nodejs application- Node Package Manager is the largest ecosystem (software registry) in the open-source code community. It helps to automate installations and updations of dependent packages
- For any types of functionality, we need to incorporate/add-in application, most probably a free, open-source Node library/package/module available with NPM
- Now a days NPM is a very popular/well-known term among the Web Development community. NPM is a package manager for Node/JavaScript packages or modules
- Developed by
Isaac Z. Schlueter, initially released inJan-2010
The package is nothing but just a collection of code ready to use, it is usually managed and maintained with a package management system.
Sometimes word Package is alternatively used in place of Module. Package/Module is nothing but a single or bunch of reusable code file(s) wrapped together with a special file named Package.json
- What is a Package?
- A Packages contains all the files which are needed for a module(s)
- What is a Module(s)?
- Module(s) are the JavaScript libraries that can be included in Node projects as per the requirement
- Software that automates installing and updating packages as and when required
- Package Management System Software deals with what version developer/user needs, and it also manages dependencies
- Code/program/Instructions that another set of Code/program depends on to function (Like We use particuler set of code in our app, it is a dependency - our app depends on it. It may be possible that current code depends on some other code and have some other dependencies)
- It provides an online repository for Node/NodeJs Packages/modules/utilities which we can easily search at
- (website: https://www.npmjs.com/)
- It equips/provides a CLI (Command Line Interface) utility to install Node/NodeJs Packages
- CLI helps/allows the developers to interact with their systems locally also perform version management and dependency management for Node/NodeJs Packages
- NPM allows/helps developers to publish their solution(s) code/package/module into NPM Registry so that other developers facing the same issue can re-use the code by installing the required NPM package/module
- NPM is a way to share code with other developers worldwide, also re-use the code of other developer and easily manage different version of the code base
- Helps to incorporate the pre-built packages into the project
- Assists in downloading various stand-alone tools which can be used any time/right away (adapting any packages as and when the need arises )
- With
npxwe can run and use packages without downloading it - Developers can share their code with other worldwide NPM users/developers
- It helps in restricting the code to the specific or particular group of developers (forming virtual team using orgs/organizations)
- Helps in managing and maintaining various versions of codes and their dependencies
- NPM automatically updates the application with the update in the codes
- Completely free and open source
- Simpler than SOAP (Simple Object Access Protocol)
- Default package manager of Nodejs
- World's largest software registry (The largest ecosystem of open-source libraries)
- Fully developed in JavaScript
- Manage local and global dependencies of project/application/tool
- An easy and fast CLI (Command Line Interface) utility to install packages/modules/solutions
In this section, we will learn how to set up a local development environment by installing NPM:
- NPM bundled and shift with Nodejs. In order to have NPM on our machine, we just need to download and install Node
- NPM is pre-built with Node/Nodejs so it gets installed automatically - no need to install it separately
- To verify node/npm available/installed on machine, type command:
node -v/node --versionnpm -v/npm --version
- If Node not available on machine than download and Install latest nodejs installer as per your OS, and continue installation (website: https://nodejs.org/en)
- One can install LTS (Long Term Support) verion or current latest version anything is fine
-
After installation, check installed version of node and npm or verify installation by using command:
- To get/check version of node, command:
node -v/node --versionOR - To get/check version of npm, command:
npm -v/npm --version
- To get/check version of node, command:
-
To install specific npm version command:
- Syntax:
npm install -g npm@version_number(-gflag is to install globally) - Command:
npm install -g [email protected],npm install -g [email protected]
- Syntax:
-
If any permission error occurs:
-
MacOS
- Run any node/npm commands as
sudooradministrator, command:sudo npm install -gorsudo npm i -g
- Run any node/npm commands as
-
Windows
- Open Command Prompt/Terminal Window with Administrative privileges, Right Click on Terminal (Windows Command Prompt) Icon/Programm -> Choose Run As Administrator
-
- Getting/Using help with Node/NPM is pretty simple, generally
-hor-helpor--helpflag is used to get/show help about npm or any other npm command - Syntax: Get NPM help:
npm -hORnpm -helpORnpm --help - Syntax: Get any NPM command help:
npm <command_name> -hORnpm <command_name> -helpORnpm <command_name> --help npm -hORnpm -helpORnpm --helpcommand shows typical usage of NPM and various sub-flag/options available to use- Example: To get npm help:
npm -hORnpm -helpORnpm --help - Example: To get help of install command:
npm install -hORnpm install -helpORnpm install --help
Package.json is an important file for any Node or similar applications, let learn and understand some facts about it:
- For any Node application, the
package.jsonfile is the heart or main file of the entire application package.jsonfile is basically the entry point ormanifest filethat contains the genericmetadata/information about Node application-project in the form of (application name, version, author, license, dependencies, etc.) of the project- It is present in the
root directoryof any Node/Angular/React or similar application and/ornode_modulesfolder, used to define/contains properties of a package (metadata specific to the project) - If we want to create a public package/module or many peoples working on the same distributed project/package/module then its advisable to create a package.json file at the root of the project
- One can create package.json file with different ways like:
- manually
- through node/npm command:
npm init, - with yarn command:
yarn init
- To create package.json file use npm command:
npm initand answer basics questions related to the application like application name, version, author, license details, project/application description, dependencies, etc.- command:
npm init- initialize the project and create a package.json file
- command:
- command:
npm init -yORnpm init --yes(the-yor--yesflag take default answers of questions and create a package.json file directly)-yOR--yesflag skips all questions and creates package.json with default values
Syntax & Example:
3.3.1.1-package-json-basic/package.json
{
"name": "learning-package-json",
"version": "1.0.0",
"description": "Introduction to package.json with creation by using \"npm init\" command",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"package",
"init",
"learning",
"npm"
],
"author": "Dinanath Jayaswal",
"license": "MIT"
}
Syntax & Example:
3.3.1.3-package-json-yes/package.json
{
"name": "3.3.1.3-package-json-yes",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC"
}
Each package or dependencies have proper/meaningful version - let us learn about SemVer or Semantic Versioning SemVer | Semantic Versioning now!
- package-lock.json is automatically generated for any operations where npm modifies
node_modulesorpackage.json
Package.json files provide the following benefits:
- Holds various metadata relevant to the project
- contains project-specific metadata/information (application name, version, author, license, dependencies, etc.)
- Manage dependencies of project/application
- Any package and its version (popular npm packages are: nodemon, express, lodash, moment, etc.)
- Scripts section: (Helps to write initial build scripts for project/application)
- Commands/Process/Steps to run initially/by default
| Files/Folders | Description |
|---|---|
**Folders:** |
|
| node_modules | The packages specified in package.json file are installed into this folder (node_modules) when we run npm install command. Also provides npm packages/dependencies to the entire workspace/projects (node_modules folder consists of all installed packages mentioned in package.json) |
**Files:** |
|
| package.json | Contains the packages to build and run our angular application, consists of Node/NPM library/package/module dependencies for application development. Custom script can also be added in as per requirements It contains two sets of packages: 1. dependencies: The dependencies are essential for running the application, and 2. devDependencies: The devDependencies are only required to develop the application These packages mentioned in package.json are installed into the node_modules folder by the Node Package Manager (npm), when npm install command is executed."scripts" property contains the useful and important npm commands needed to run/serve project |
| package-lock.json | Provides version information for all packages installed into node_modules by the npm client |
-
Change is nature's thumb rule, so every tool/technology/framework/library developed have to room for improvement
-
Versioning:
- Specifying what version of a set of code this is
- It helps others to track if a new version has come out/released
- This allows to watch for a new feature or to watch for
breaking changesif any
-
Semantic:
- The word
semanticimplies that something conveys meaning (meaningful) - Semantic versioning follows certain rules while determining the current version number
- The core of Semantic versioning system/rule:
MAJOR.MINOR.PATCH 1.0.0
- The word
-
Many Software Development companies worldwide and software giant like Google decided and declared that their frameworks and tools version will be upgraded as per
Semantic Versioning System -
SemVer or Semantic Versioning or Semantic Versioning Systemhas 3 main components as =x.x.x i.e. Major.Minor.Fix Patch version/release, example: 0.0.1-
Fix Patch- can increase any time with bug fixes/patch release|Bug fixes, simple changes|Some bugs were fixed and code works fine.1.0.1 -
Minor version- increases with every feature release which does not break any functionalities|Adding/changing new/old feature which does not break existing functionality in application|Some new features added and code works fine1.1.0 -
Major version- Break in the functionalities, extraordinary feature achievements|Totally new/fresh features which extra ordinary breaking changes|Big changes & new functionalities added and code works fine2.0.0
-
-
SemVer or Semantic Versioning symbols:
-
^ caretsign = upgrade if change in Minor/Patch version like 1.x.x -
~ tilde/tildasign = upgrade if change in Patch version like 1.0.x
-
website: semver.org | https://semver.org/
-
To set desired default values in package.json
- command
npm config set init-author-name "Dinanath Jayaswal" - OR
npm set init-license "MIT"
- command
-
To get default values of package.json
- command
npm config get init-author-name - OR
npm get init-license
- command
-
To unset any default values set in package.json
- command
npm config delete init-author-name - OR
npm delete init-license
- command
Syntax & Example:
3.5-package-json-set-default-values/package.json
{
"name": "3.5-package-json-set-default-values",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "Dinanath Jayaswal",
"license": "ISC"
}
- NPM allows/helps developers to publish their solution(s) code/package/module into
NPM Registryso that other developers facing the same issue can re-use the code by installing the required NPM package/module - All packages live/exist in an online NPM registry
- One can just visit (website: https://www.npmjs.com/) and simply
searchfor required solution/package/module
- website: https://www.npmjs.com/
- Search for required packages and install accordingly
Here is the list of various commonly used, popular and famous npm packages available:
| Package/Module | Description |
|---|---|
express |
HTTP helpers web framework for node command to install: npm install express |
body-parser |
Body parsing middleware |
nodemon |
Utility to monitor any changes in source code and reload the application automatically (restart/reloads application/server if any changes done by the developer). |
babel-core |
Compile/Transpile ES6 code to ES5 code |
lodash |
Makes working with JavaScript easier |
react |
Helps to create ReactJs applications |
request |
Helps in making HTTP calls most easily/most quickly |
async |
Helps to work with async JavaScript applications |
moment |
Parse, validate, manipulate and display dates |
angular/cli |
Generating and serving an Angular project via a development server |
The package is nothing but just a collection of code ready to use, it is usually managed and maintained with a package management system.
Sometimes word Package is alternatively used in place of Module. Package/Module is nothing but a single or bunch of reusable code file(s) wrapped together with a special file named Package.json.
Packages are categorized under two different categories depending on their mode of installation done by developer:
- Local Packages
- Global Packages
- Local Packages are
installed within the current project/application directorywhere one will be executing thenpm installcommand and will be accessible byonly current project/application - If any package required or makes sense
only to a specific project/applicationthan it is advisable to install the package locally in the current project folder
Syntax:
npm install <package_name>ORnpm i <package_name>
Example:
npm install moment
- Global Packages are installed at a single/central place (
path environment variables) in your system and they can be used byany of the projects present in your system - Some packages are commonly used in multiple angular/node projects/application in such scenarios its advisable to install those packages globally so that its available under
path environment variables - Globally installed dependencies are not part of/not residing in
package.jsonand/ornode_modules - We can use the
-gflag to install the package globally
Syntax:
npm install <package_name> -gORnpm i <package_name> -g
Example:
npm install moment -g
- If any package required or makes sense
only to a specific project/applicationthan it is advisable to install the package locally in the current project folder - At npm official website: https://www.npmjs.com/ we can search for the specifically required package and have all help/detailed information of the package
- To install any third-party library or npm package in Node application use command:
npm install <package_name>ORnpm i <package_name>(it download and install packages also makes/add an entry in package.json file) - All packages/modules and dependencies mentioned in
package.jsonget installed under the foldernode_modules
Syntax:
npm install <package_name>ORnpm i <package_name>
Example:
npm install moment
Syntax & Example:
4.3.1-Installing Local Packages-npm-i/package.json
{
"name": "npm-local-package-installation",
"version": "1.0.0",
"description": "Learn to install npm packages locally",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"npm",
"node",
"local",
"package",
"npm",
"install"
],
"author": "Dinanath Jayaswal",
"license": "MIT",
"dependencies": {
"moment": "^2.24.0"
}
}
- As per the recent NPM version, whatever npm package we install with command
npm i <package_name>thepackage.json by default take a record/an entryof the same as dependencies (in old/past version we use to provide--saveflag-likenpm i <package_name> --save) - To save the package/module in a package.json as a dependency for current project, we must have to use following command:
Syntax:
npm install <pakcage_name> --saveORnpm i <pakcage_name> --save
Example:
npm install moment --save
- Development or Developer dependency based package must be part of devDependency in package.json (packages needed for develpoment and are not required for production)
Syntax:
npm install <pakcage_name> --save-devORnpm i <pakcage_name> --save-dev
Example:
npm install @angular/cli --save-dev
Syntax & Example:
4.3.1-Installing Local Packages-npm-i/package.json
{
"name": "npm-local-package-installation",
"version": "1.0.0",
"description": "Learn to install npm packages locally",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"npm",
"node",
"local",
"package",
"npm",
"install"
],
"author": "Dinanath Jayaswal",
"license": "MIT",
"dependencies": {
"moment": "^2.24.0"
},
"devDependencies": {
"@angular/cli": "^8.3.23"
}
}
Sometimes we need to upgrade or downgrade to the specific version of a particular package. To install/setup a specific version use following command:
Syntax:
npm install <package_name>@version
Example:
npm install [email protected]
Sometimes we need to uninstall some unwanted and deprecated packages from current project/application with command npm uninstall <package_name>. As and when we uninstall some package, its entry gets deleted from package.json file and node_module folder.
Syntax:
npm uninstall <package_name>ORnpm un <package_name>
Example:
npm uninstall moment
- To remove the entry of deleted packages from package.json file (if required)
Syntax:
npm uninstall <pakcage_name> --saveORnpm un <package_name> --save
Example:
npm uninstall <pakcage_name> --save
- Uninstall/delete dev dependencies if any:
Syntax:
npm uninstall <pakcage_name> --save-devORnpm un<pakcage_name> --save-dev
Example:
npm uninstall @angular/cli --save-dev
- Global Packages are installed at a single/central place (
path environment variables) folder in your system and they can be used byany of the projects present in your system - Some npm packages are commonly used in multiple angular/node projects/applications, in such scenario, it is advisable to install those packages globally so that its available under
path environment variables - Globally installed dependencies are not part of/not residing in
package.jsonand/ornode_modules - We can use
-gflag withnpm installcommand to install a package globally
Syntax:
npm install <package_name> -gORnpm i <package_name> -g
Example:
npm install moment -g
- To get a list of global outdated packages command:
npm outdated -g
- To uninstall global packages we can use following command:
Syntax:
npm uninstall <package_name> -gORnpm un <package_name> -g
Example:
npm uninstall moment -gORnpm un moment -g
- NPM
removecommand is also used to uninstall global packages:
Syntax:
npm remove <package_name> -gORnpm rm <package_name> -g
Example:
npm remove moment -gORnpm rm moment -g
- To get the list of dependencies/packages installed in the application, one can have a manually look in
package.jsonfile or check-innode_modulesfolder but these processes are pretty time consuming, so its advisable to usenpm listcommand npm listcommand displays the tree-like structure of packages locally installed
npm list: To get list/tree of all installed dependencies (Tree of main as well as sub dependencies)
npm list --depth=0ORnpm list --depth 0: Get the list of main dependencies only (No sub dependencies)
npm list --depth=1ORnpm list --depth 1: Show package with only one ie. 1st level of dependency
- To get list of global packages:
npm list --global true --depth 0: Show list of Global packages with main dependencies only (No sub dependencies)
- Many times other developers share their application metadata and dependencies information in the form of
package.jsonwhich helps to set up the development/project environment - It is advisable to share only
package.jsonfile with other developers/team members or external world (No need to sharenode_modulesfolder) - One can simply run an npm command:
npm installto download/install all required dependencies locally as mentioned inpackage.jsonfile npm install- command is one of the most widely used and common commands of node/npm- It first creates
node_modulesfolder and installs all the packages with listed dependencies mentioned in package.json
It is important to update packages from time to time basis so that we make the best use of new features/utilities that are available/introduced with every release.
In the actual development world, there might be a newer version of the package/dependency with which we are working and installed in the project.
- To find out the outdated packages/dependencies and to get the details of current and latest versions in tabular form
Syntax:
npm outdated
Example:
npm outdated
- To update all packages
Syntax:
npm update
Example:
npm update
- To update specific package
Syntax:
npm update <package_name>
Example:
npm update moment
- To update all global packages
Syntax:
npm update -g
Example:
npm update -g
- To update specific global package
Syntax:
npm update <package_name> -g
Example:
npm update @angular/cli -g
- To update npm itself
Example:
npm install npm@latest -g
- To update and save all dependencies in package.json:
Syntax:
npm update <package_name> --save
Example:
npm update moment --save
- To update and save all dev dependencies in package.json:
Syntax:
npm update --dev --save-dev
Example:
npm update --dev --save-dev
- Note: The command
npm update, updates packages to the only Minor/Patch release (Usually, we use^ caretsign which denotes minor/patch release only) - To check and install the latest Major release we can need to use/install another npm package named
npm-check-updatesORncu- To install
npm-check-updatesuse command:npm install npm-check-updates -g
- To install
- Once
ncuinstalled, run command:npm-check-updatesORncuto get the list of all latest updated version of packages - Run command:
ncu -uto upgrade package.json file with latest versions of packages - Finally run the command:
npm installto install all updated packages from package.json
The npm list command shows up a list of unused, unwanted, extraneous packages installed just for R&D or testing purposes and also installed by mistake.
- To remove/delete/uninstall and clean such extraneous/unwanted packages we must need to use command:
Syntax:
npm pruneORnpm prune <package_name>
Example:
npm prune
This command removes such extraneous packages. If a package name is provided, then only packages matching one of the supplied names are removed.
To learn some npm package or get more detailed information about a package, one is supposed to visit/head over to (website: https://www.npmjs.com/), search for the package, read technical metadata information in the form of (use case, versions, dependencies, etc.)
The quickest, fastest and advisable way to get metadata details is to use npm commands as given below:
- Get all info/metadata or package.json file of specific/particular
<package_name>with all dependencies
Syntax:
npm view <package_name>
Example:
npm view underscore
- To get the list of only dependencies for
<package_name>
Syntax:
npm view <package_name> dependencies
Example:
npm view @angular/cli dependencies
- To get the released version of a package
Syntax:
npm view <package_name> version
Example:
npm view underscore version
- To get the all released versions of a package
Syntax:
npm view <package_name> versions
Example:
npm view underscore versions
- Visit the website: https://www.npmjs.com
- At npm official website: https://www.npmjs.com/ we can search for the specifically required package and have all help/detailed information of the package
- Search for any popular npm package/library like
underscorewebsite:https://underscorejs.org/(its a utility for widely used for JavaScript functions, JavaScript's functional programming helper library.) - Install
underscoreby using npm command:npm i underscore, (now a days as per the latest node/npm versions, we no longer need to specify--saveflag (an entry in package.json andnode_modulesdone automatically/by default)) - Create a new entry point file at the root of the package named
index.js- Include/load underscore package/module: var _ = require('underscore');
- First
package_name ie. underscoreis searched in node core module than locally as files/folders and/or then in 'node_modules' folder
- Check exact usability and use-cases of 'underscore' at website/help and use accordingly
underscore functions - Check the files output by using node command:
node index.js
Syntax & Example:
5-using-external-third-party-package/package.json
{
"name": "using-external-thir-party-package",
"version": "1.0.0",
"description": "Learn using-external-thir-party-package",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"using-external-thir-party-package"
],
"author": "Dinanath Jayaswal",
"license": "MIT",
"dependencies": {
"underscore": "^1.9.2"
}
}Syntax & Example:
5-using-external-third-party-package/index.js
// include/load underscore library
var _ = require('underscore');
// use underscore library
var isContains = _.contains(['hi', 'hello', 'hey', 'hola'], 'hello');
console.log('It contains hello:', isContains);
Code/program/Instructions that another set of Code/program depends on to function (Like We use particuler set of code in our app, it is a dependency - our app depends on it. It may be possible that current code depends on some other code and have some other dependencies).
There are two types of dependencies:
- Application/project dependencies
- Dev dependencies
The dependencies are essential for running the application, basic common packages need every-time.
- The command
npm i <package_name>will create one entry inpackage.jsonfile and all required dependencies get installed undernode_modulesfolder- Command:
npm install <package_name>
- Command:
- In the past/previous npm version, all dependencies use to install inside
folder->folder->folderetc., but now as per latest node/npm - all dependencies are getting installedat the root node_modulesfolder to avoid deeply nested long path, characters limitations in file/folder naming convention
Global dependencies: npm install <package_name> -g, it is installed in common program files folder
- Development dependencies like unit testing tools/packages, static analysis based packages, code bundling tools are not supposed to go to the production environment where we deploy the applications
- Use/Supply
--save-devflag to save provided package under dev dependencies (devDependencies) section of package.json filenpm install <package_name> --save-dev
Note: All dependencies are getting installed under node_modules folder but segregated only in package.json file as
dependencies & devDependencies.
Global dependencies: npm install <package_name> -g, it is installed in common program files folder path environment variables
- It is advisable not to Share as well as check-in
node_modulesfolder in git or any other Version Control System/Revision Control/SCM/SVC/SVN tools
- SCM - Software Configuration Management
- SCM - Source Control Management Tool
- VCS - Version Control System
- SVC - Software Version Control
- SVN - Subversion (Software Version)
- Create a
.gitignorefile in the local git repository folder - List down all the files/folder which we want to ignore while check-in/check-out code
.gitignore
node_modules/
Scripts section of package.json file run by default, it is very handy when you want to execute/run/initiate some custom tasks from package.json.
Scripts section consists of custom command or scripts to use in application i.e. npm test or npm build or npm serve or npm start etc. Here test, build, serve, start is a custom script that executes default tasks/activities as per logic/requirements.
- Create a package.json with the command:
npm init -y - Change/replace the existing scripts
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},To
"scripts": {
"start": "node app.js"
},- Create a new .js file named as
app.js, write some statements with console.log - Run command
npm startto initiate application and get output at terminal console
Syntax & Example:
package.json
{
"name": "8.1-creating-runnning-npm-script",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"start": "node app.js"
},
"keywords": [],
"author": "Dinanath Jayaswal",
"license": "ISC"
}Syntax & Example:
app.js
console.log('NPM start... app.js running');
- Create a new directory on local to store new library/package, command:
mkdir maths-lib - Change directory to explore inside, command:
cd maths-lib - Create/Instantiate new package.json file, command:
npm init -yornpm init --yes - Create a new file named
index.jsas the entry of package, create and export some function as per logic and requirements of the package
To Publish a package to online NPM registry, the developer should have User Credentials:
- Create an account/register/sign-up at
https://www.npmjs.com/- by visiting in a browser or
- at the command prompt using the command:
npm adduser
- If a user already exists than sign-in by using the command:
npm loginand enter credentials with the email address - To publish a package use command:
npm publish(if any error related to package name pops-up, change the name in package.json with some unique identifier as"name":maths-lib-1or so...)
- To check/verify/install and use
maths-lib-1package, create a new folder for fresh application and try to install package with command:npm install maths-lib-1 - To use/call/load previously created
maths-lib-1package/module in new appliacation, create a newindex.jsfile andimport/load maths-lib-1package with 'require('maths-lib-1')', try to call its methods - execute file with command:
node <file-name>ornode index.js
- Make necessary changes in any .js file of the previously created package by adding and exporting some more functions/logic
- change version manually in package.json file or run the command:
npm version majorORnpm version minorORnpm version patch
- To publish edited package command:
npm publish - Go to other application and run update old package to new version command:
npm update - Now in any .js file try to call latest methods
- execute file with command:
node <file-name>
Syntax & Example:
9-creating-publishing-package/maths-lib/index.js
module.exports.add = function (num1, num2) {
return num1 + num2;
}
module.exports.subtract = function (num1, num2) {
return num1 - num2;
}
module.exports.multiply = function (num1, num2) {
return num1 * num2;
}
module.exports.divide = function (num1, num2) {
return num1 / num2;
}
module.exports.oddEven = function (num1) {
if(num1 % 2 === 0){
return 'Even Number';
} else {
return 'Odd Number';
}
}Syntax & Example:
9-creating-publishing-package/using-published-package/index.js
var mathsLib = require('maths-lib-1');
var add = mathsLib.add(10,20);
console.log(add);
var oddEvenNumber =mathsLib.oddEven(39);
console.log(oddEvenNumber);
Reference: - https://nodejs.org
Reference: - https://www.npmjs.com/
| Node-NPM command | Description |
|---|---|
npm init -y |
Skips questions and creates package.json with default values) |
npm i <package_name> |
Install |
npm i <package_name> -S |
Save package as Dependency in package.json |
npm i <package_name> -D |
Save package as devDependency in package.json |
-g |
Global |
npm -v |
Version |
Reference: - https://docs.npmjs.com/misc/config
| Node-NPM command | Description |
|---|---|
node -v OR node --version |
To get Node Version |
npm -v OR npm --version |
To NPM Node Version |
npm install -g @angular/cli |
To install Angular CLI globally |
npm -h OR npm -help OR npm --help |
To get help on any node/npm command |
npm install <package_name> OR npm i <package_name> |
To Install Node-NPM Package |