NPM

Installing npm

• To check if it’s installed, open your command line or terminal and type

node -v
npm -v

Semantic Versioning

• This is semantic versioning, and it’s important for managing package updates without breaking your project. Here’s a quick breakdown:

  • Major version (1.x.x): Introduces breaking changes.
  • Minor version (x.1.x): Adds functionality in a backwards-compatible manner.
  • Patch version (x.x.1): Fixes bugs without adding new features.

• The ^ symbol allows minor and patch updates. Using ~ would only allow patch updates.

Package Management

• Install packages defined in the package.json file

npm install

• Install a package locally

npm install <package_name>

• Install a specific version of a package

npm install <package_name>@<version>

• Install a package globally

npm install <package_name> --global

• Install and save a package as a dependency

npm install --save <package_name>

• Install and save a package as a development dependency

npm install --save-dev <package_name>

• Updating Packages

npm update <package_name>

Handling Global Packages

• List globally installed packages

npm list -g --depth=0

• Find the location of globally installed packages

npm root -g

Dependency Management

• Update installed packages

npm update

• Check for outdated packages

npm outdated

• Uninstall a package

npm uninstall <package_name>

• Remove packages not listed in the package.json file

npm prune

Scripts

• Run the start script defined in package.json

npm start

• Run the test script defined in package.json

npm test

• Run a custom script defined in package.json

npm run <script_name>

Publishing

• Initialize a new package.json file

npm init

• Publish a package to the npm registry

npm publish

• Update the version number in package.json

npm version <version>

Miscellaneous

• Search for packages on the npm registry

npm search <keyword>

• Get detailed information about a package

npm info <package_name>

• List installed packages

npm ls

• Get help with npm commands

npm help

Reinstall

• Remove node modules

rm -rf node_modules

• Reinstall

npm i

Useful npm run setting

• Here are some common and useful npm run scripts you can define in your package.json file

Prettier

• npm run prettier:check: Checks if files are formatted
• npm run prettier:write: Formats the code in the entire project

"scripts": {
  "prettier:check": "prettier --check .",
  "prettier:write": "prettier --write ."
}

Jest

• npm run test: Runs all the tests
• npm run test:watch: Watches for changes and reruns the tests
• npm run test:coverage: Runs tests and generates a code coverage report

"scripts": {
  "test": "jest",
  "test:watch": "jest --watch",
  "test:coverage": "jest --coverage"
}

ESLint

• npm run lint: Lints all files in your project.
• npm run lint:fix: Automatically fixes fixable linting errors.

"scripts": {
  "lint": "eslint .",
  "lint:fix": "eslint . --fix"
}