JavaScript - Package Manager

In JavaScript, a package manager is a tool that makes simple to install, manage, and update libraries, or packages, in your project. You can save time and add functionality without having to start from scratch by using these packages, which are reusable code pieces provided by other developers.

Need of a Package Manager

Suppose there were no package managers. The following duties were likely to be completed by hand in that condition −

• Find all of the packages that are suitable for your project.

• Verify that the packages do not include any known vulnerabilities.

• Pick up the packages.

• Place them where they belong.

• Keep an eye out for any developments on each of your packages.

• Update all packages if a new release takes place.

• Get rid of any packages that are unnecessary.

It takes a lot of effort and time to manually arrange tens or even hundreds of things. The two most common package managers in JavaScript are as follows −

Node Package Manager (npm)

Node Package Manager, or NPM, is a platform that makes it easier for developers to use and share JavaScript code. It is used with Node.js, a JavaScript runtime that makes JavaScript work not only on a browser but also on a server.

This is what NPM does −

• NPM makes it simple to add, modify, and remove code parts known as packages. These packages work similarly to the building blocks that programmers use to add specific features to their applications, including managing user input or connecting to a database.

• Using commands in the terminal, developers may quickly set up or modify code with NPM (for example, npm install to add a package).

• NPM offers millions of packages that people from all around the world contribute to, so if you need code for a common task, someone has undoubtedly already created a package for it.

• Many packages are interdependent. NPM keeps an eye on those links and ensures that you have all the resources needed for the code to run.

Commands

Here are some of the commands that you can use to take the benefits of NPM −

• npm install "package-name": Using this commands you can install a package.

• npm uninstall "package-name": By this command you are able to remove a package.

• npm update "package-name": Using this command you can update a package.

• npm init: By this command you can set up a new project and create a package.json file.

The package.json file

Every JavaScript project, whether Node.js or a browser application, can be scoped as a npm package that includes its own package information and package.json file is used to describe the project.

When npm init is used to start a JavaScript/Node.js project, package.json is created with the following basic metadata provided by developers −

• name: the name of your JavaScript library/project

• version: It shows the version of your project. This field is often ignored in application development because there looks to be no need for versioning open-source libraries. But it can be used as a source for the deployment's version.

• description: The project's description.

• license: The project's license

Yarn

Yarn, like NPM, is a platform that allows developers to manage code packages. Facebook created it to address certain problems that developers experienced with NPM, like performance and stability.

The installation method is divided into three steps −

• Resolution: Yarn begins resolving dependencies by sending queries to the registry and iteratively looking for each dependency.

• Fetching: Next, Yarn checks a global cache directory to see if the required package has been downloaded. If it has not already, Yarn gets the package's tarball and saves it in the global cache so it can work offline and avoid downloading dependencies several times. Tarballs containing dependencies can also be placed in source control for full offline installations.

• Linking: Finally, Yarn connects everything together by copying all of the required files from the global cache to the local node_modules directory.

Commands

Here are some of the commands you can use for using yarn −

• yarn add "package-name": You can use this command for installing a package.

• yarn remove "package-name": You can use this command for removing a package.

• yarn upgrade "package-name": Use this command to update a package.

• yarn init: You can set up a new project and create a package.json file.

Yarn uses a lock file (yarn.lock) to verify that all developers on your team are using the same version of packages. This helps to avoid bugs caused by version variations.

Why Use a Package Manager?

Both npm and Yarn are widely used, and the decision between the two is frequently based on personal or project preferences. Here are the reasons why you should use package manager −

• Save time: It saves time by easily installing and utilizing existing libraries.

• Dependency Management: Automatically manage libraries that your chosen libraries require.

• Easy Updates: When upgrades or security updates are available, packages can be updated rapidly.