Difference between npm and yarn

NPM and Yarn are package managers that help to manage a project’s dependencies. A dependency is, as it sounds, something that a project depends on, a piece of code that is required to make the project work properly. We need them because managing the project’s dependencies is a difficult task and it quickly becomes tedious, and out of hand when the project grows. By managing the dependencies, we mean to include, un-include, and update them.

npm: It is a package manager for the JavaScript programming language. It is the default package manager for the JavaScript runtime environment Node.js. It consists of a command-line client, also called npm, and an online database of public and paid-for private packages called the npm registry.

yarn: It stands for Yet Another Resource Negotiator and it is a package manager just like npm. It was developed by Facebook and is now open-source. The intention behind developing yarn(at that time) was to fix performance and security concerns with npm.

The differences between npm and yarn are explained below:

Installation procedure

• npm: npm is installed with Node automatically.
• yarn: To install yarn npm have to be installed.

  npm install yarn --global

The lock file

• npm: NPM generates a ‘package-lock.json’ file. The package-lock.json file is a little more complex due to a trade-off between determinism and simplicity. Due to this complexity, the package-lock will generate the same node_modules folder for different npm versions. Every dependency will have an exact version number associated with it in the package-lock file.
• yarn: Yarn generates a ‘yarn.lock’ file. Yarn lock files help in easy merge. The merges are predictable as well, because of the design of the lock file.

Output log

• install: The npm creates massive output logs of npm commands. It is essentially a dump of stack trace of what npm is doing.
  
• add: The yarn output logs are clean, visually distinguishable and brief. They are also ordered in a tree form for understandability.
  

Installing global dependencies

• npm: To install a global package, the command template for npm is:

  npm install -g package_name@version_number

• yarn: To install a global package, the command template for yarn is:

  yarn global add package_name@version_number

The ‘why’ command:

• npm: npm yet doesn’t has a ‘why’ functionality built in.
• yarn: Yarn comes with a ‘why’ command that tells why a dependency is present in the project. For example, it is a dependency, a native module, or a project dependency.

License Checker

• npm: npm doesn’t has a license checker that can give a handy description of all the licenses that a project is bound with, due to installed dependencies.
• yarn: Yarn has a neat license checker. To see them, run

  yarn licenses list

  

Fetching packages

• npm: npm fetches dependencies from the npm registry during every ‘npm install‘ command.
• Yarn: yarn stores dependencies locally, and fetches from the disk during a ‘yarn add‘ command (assuming the dependency(with the specific version) is present locally).

Commands changed in yarn after npm

command	npm	yarn
Install dependencies	npm install	yarn
Install package	npm install package_name npm install package_name@version_number	yarn add package_name yarn add package_name@version_number
Uninstall package	npm uninstall package_name	yarn remove package_name
Install dev package	npm install package_name –save-dev	yarn add package_name –dev
Update dev package	npm update package_name npm update package_name@version_number	yarn upgrade package_name yarn upgrade package_name@version_number
View package	npm view package_name	yarn info package_name
Global install package	npm install -g package_name	yarn global add package_name

Commands same for npm and yarn:

npm	yarn
npm init	yarn init
npm run [script]	yarn run [script]
npm list	yarn list
npm test	yarn test
npm link	yarn link
npm login or logout	yarn login or logout
npm publish	yarn publish