An Introduction to NPM Package Manager

npm is the standard package manager for Node.js. It is one of the largest software registries where you can find millions of JavaScript codes commonly known as Packages.

With npm, you can install, update, and manage dependencies for your project.

What are Packages?

Simply packages are bundles of JavaScript code developers have written to solve particular problems. These packages are reusable, you can install them into your project using npm instead of writing the code from scratch.

1. Initialization and Configuration

• Creates a new package.json file for your project. It prompts for project details like name, version, description, etc.

• Use npm init -y to skip prompts and generate a default package.json.

npm init

2. Installing Packages

• Installs all dependencies listed in the package.json file into the node_modules folder.

npm install (or npm i)

• Installs a specific package and adds it to your dependencies in package.json.

npm install <package-name>

• Installs a package and adds it to devDependencies in package.json.

npm install <package-name> --save-dev

• Installs a specific version of a package.

npm install <package-name>@<version>

• Installs a package globally, making it available across your system.

npm install -g <package-name>

3. Removing Packages

• Removes a package from node_modules and updates the package.json file.

npm uninstall <package-name>

• Removes a globally installed package.

npm uninstall -g <package-name>

4. Updating Packages

• Updates all outdated packages listed in dependencies and devDependencies.

npm update

• Updates a specific package to its latest version.

npm update <package-name>

5. Managing Dependencies

• Displays a tree of all installed dependencies for your project.

npm list

• Lists all globally installed packages.

npm list -g

• Removes unused packages from the node_modules folder.

npm prune

6. Running Scripts

• Executes a custom script defined in the scripts section of your package.json file.

npm run <script-name>

"scripts": { 
  "start": "node app.js", 
  "test": "jest" 
}

To run:

npm run start
npm run test

• Shortcut for npm run start, if a start script is defined.

npm start

7. Cache Management

• Clears the npm cache to resolve potential issues.

npm cache clean --force

8. Package Version Management

• Installs a specific version of a package.

npm install <package-name>@<version>

• Lists all available versions of a package.

npm view <package-name> versions

• Shows detailed information about a package, including its dependencies, versions, and maintainers.

npm info <package-name>

9. Publishing and Sharing

• Publish your package to the npm registry.

npm publish

• Removes a published package from the npm registry.

npm unpublish <package-name>

10. Miscellaneous Commands

• Displays the current version of npm installed on your system.

npm version

• Displays help information for npm commands.

npm help

• Scans your project for security vulnerabilities in dependencies.

npm audit

• Automatically fixes vulnerabilities if possible.

npm audit fix