What is npm in Node.js?
As the standard package manager for Node.js, npm (Node Package Manager) is a group of software tools that automates the process of installing, updating, customising, and uninstalling computer programs for an operating system in a consistent way. Online repositories for Node.js packages and modules, which can be searched on search.nodejs.org, and a command-line tool for installing, managing versions, and handling dependencies of Node.js packages are its two main features. Node.js projects require extra libraries and tools, which npm essentially assists you in managing.
Why npm is Popular
Its crucial role in supporting the flourishing ecosystem of Node.js is partly responsible for npm’s enormous popularity. This is the reason it’s so revolutionary:
- JavaScript Everywhere: Node.js enables programmers to utilise JavaScript outside of the browser, especially for networking and server-side applications. By allowing frontend developers who are already comfortable with JavaScript to use the same language and concepts for server-side code without having to learn a whole new tool, npm goes beyond this. The notion of “JavaScript everywhere” is a powerful lure.
- Huge Ecosystem of Libraries: npm is home to the world’s largest single-language code repository, with an estimated 500,000 packages as of January 2017. It’s likely that someone has already solved and published a package for practically any general issue you might run into when developing Node.js because of this extensive collection. Developers may now concentrate on application-specific logic instead of rewriting boilerplate code, which significantly reduces development time.
- Ease of Use and Publishing: npm makes it incredibly simple for anyone to use and publish tools and libraries. Because of its ease of use, the Node.js community has grown quickly by fostering cooperation and sharing. The activity of the community is one of Node.js’s advantages.
- Performance and Efficiency: Node.js is renowned for its speed, portability, and high performance, particularly for real-time, data-intensive applications. This is mostly because of its event-driven, non-blocking I/O model. Developers can install modules knowing they are in line with Node.js’s performance characteristics because the libraries on npm are constructed with this non-blocking philosophy.
- Structured Project Management (
package.json
): Thepackage.json
file, which is typically located at the root of a Node.js project, is the foundation of npm’s dependency management system. This file, which contains necessary metadata and configurations, acts as a manifest for your project. - Using the command line, you can run
npm init
to create a newpackage.json
file. After you respond to a series of questions regarding your project (such as its name, version, description, and entry point), the interactive program will create the file. - You will then be asked for details, such as:
- Following confirmation, a
package.json
file is produced: - Along with other metadata like the author and license, this file lists all the modules your project requires and the versions that have been installed. Since the
node_modules
folder is normally not added to control, npm automatically changes this file when you install packages to track dependencies and ensure predictable builds. This is particularly helpful when working on a project with others. For speed and security, apackage-lock.json
file is also generated, which contains comprehensive information on installed modules. - Installing Packages: The primary way to add external libraries is using the
npm install
command.- Local Installation: By default,
npm install <package-name>
installs packages into anode_modules
subfolder within your current project directory. These locally installed packages are accessible within your Node.js application using therequire()
function. - This command downloads Express.js and its dependencies into
node_modules
and, as of npm version 5, automatically adds it to thedependencies
property in yourpackage.json
file. If you need to install a package only for development and testing (e.g., a testing framework), you can use the--save-dev
(or-D
) flag; these will be listed underdevDependencies
inpackage.json
and won’t be installed in a production environment unless explicitly requested. - Global Installation: Some npm modules are command-line programs designed to be used from any directory on your system. These are installed globally using the
-g
or--global
flag. For example,nodemon
is a global utility that automatically restarts your Node.js application when code changes are detected, saving developers from manually restarting the server. - Once installed globally, you can run it directly from your terminal:
- This will start your
app.js
and restart it every time you save changes to your code.
- Local Installation: By default,
- Running Scripts: The
"scripts"
section in thepackage.json
file also lets you define custom scripts. These scripts automate a number of processes, such as building the project, establishing a server, and conducting tests. - You can execute these scripts using
npm run <script-name>
: - You can frequently use
npm start
ornpm test
straight, without therun
keyword, for individual scripts like"start"
or"test"
.
Essentially, npm serves as your Node.js projects’ intelligent personal assistant and well-structured public library. You can “check out” and utilise the thousands of pre-written “books” (modules) on about any subject you can think of from the library. The CLI tool, your personal assistant, takes care of all the tedious tasks of locating, downloading, organising, and updating these books so you can concentrate on creating your own “story” the special elements of your application. npm’s smooth integration and abundance of resources are the main reasons it’s so widely used and essential in Node.js development.