Common NPM commands

NPM (Node Package Manager) is the package management tool for Node.js, used to install, manage, and share JavaScript code. Below are some commonly used NPM commands and their usage.

Initialize a Project

Use the npm init command to create a new package.json file, which describes the project information and dependencies.

npm init

After running, you will be prompted to enter details like the project name, version, description, etc. To quickly generate a default configuration, add the -y flag:

npm init -y

Install Dependencies

Install Production Dependencies

Production dependencies are packages required for the project to run. Use the --save or -S flag (default behavior in NPM 5+):

npm install lodash

Equivalent to:

npm install lodash --save

Install Development Dependencies

Development dependencies are only needed during development, such as testing tools or build tools. Use the --save-dev or -D flag:

npm install jest --save-dev

Global Installation

Globally installed packages can be used anywhere, typically for command-line tools like nodemon:

npm install nodemon -g

Install a Specific Version

You can specify a package version or version range:

npm install express@4.17.1

Or use semantic versioning:

npm install express@"^4.17.0"

Uninstall Dependencies

Use the uninstall or un command to remove a package:

npm uninstall lodash

To also remove the dependency from package.json, add --save or --save-dev:

npm uninstall lodash --save
npm uninstall jest --save-dev

Update Dependencies

Update a Single Package

Use the update command to update a package to the latest version:

npm update lodash

Update All Packages

Update all dependency packages:

npm update

Check for Outdated Packages

Use the outdated command to see which packages need updating:

npm outdated

Run Scripts

Script commands can be defined in package.json and executed with npm run:

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

Run a script:

npm run test

start and test are special scripts and can omit run:

npm test

View Package Information

View Installed Packages

List all installed dependencies for the project:

npm list

Add the --depth flag to limit the display hierarchy:

npm list --depth=0

View Package Details

Use the view or info command to view detailed information about a package:

npm view express

Publish a Package

Log in to NPM

First, log in to your NPM account:

npm login

Publish the Package

Run the following in the project directory:

npm publish

Update the Version Number

Before publishing a new version, update the version number using the version command:

npm version patch  # Minor version update
npm version minor  # Medium version update
npm version major  # Major version update

Clear the Cache

NPM caches downloaded packages. To clear the cache, use:

npm cache clean --force

Configure NPM

View Configuration

View the current NPM configuration:

npm config list

Set a Mirror Source

Switch to the Taobao mirror source:

npm config set registry https://registry.npmmirror.com

Revert to the default source:

npm config set registry https://registry.npmjs.org

Other Common Commands

Check Package Security

Use the audit command to check the security of project dependencies:

npm audit

Fix security issues:

npm audit fix

Execute npx Commands

npx is used to temporarily install and run packages:

npx create-react-app my-app

View Help

View help information for NPM commands:

npm help

Or view help for a specific command:

npm help install