yarn.md

Yarn

v1

Install dependencies:

yarn
yarn install # or this
yarn install --frozen-lockfile # for CI

Add a dependency:

yarn add <package name>
yarn add <package name> --dev # for a dev dependency
yarn global add <package name> # for a global install

Upgrade a dependency:

yarn upgrade <package name>
yarn upgrade-interactive # interactive way of upgrading

Remove a dependency:

yarn remove <package name>

Note: No need to specify a flag, e.g. --dev.

Run a user-defined script:

yarn dev # for a `dev` entry in `scripts` in `package.json`
yarn run dev # or this

Note: To pass arguments just add them like so: yarn dev --foo --bar

Run locally installed CLIs:

yarn speed-test # for running `speed-test` if specified in `package.json`

Generate a yarn.lock file from a package-lock.json:

yarn import

Note: Delete the package-lock.json file if you intend to use Yarn (v1), and use the yarn.lock file instead.

Generate a list of licenses from your dependencies:

yarn licenses generate-disclaimer

Check if installed packages are currently outdated:

yarn outdated

Enforce usage of a specific version of Yarn:

yarn policies set-version <version>

Note: This will generate a .yarnrc file, and download a Yarn executable to .yarn/releases/. These should be committed to source control.

Enable PnP (i.e. Plug’n’Play):

rm -rf node_modules
yarn --pnp

Note: This will remove the node_modules folder (unnecessary), create a yarn.lock (if not already present), add installConfig.pnp: true to package.json, and generate a .pnp.js file and a .pnp/ folder. You should commit the .pnp/ folder to source control, and ignore the .pnp.js file.

Links

• Yarn v1
• Migrating from npm – CLI commands comparison (v1)
• Plug’n’Play (v1)
• CLI commands (v1)