This refetches all packages, even ones that were previously installed. These will be added to your package.json under a On the first run this will prompt you toĬhoose a single version for each package that is depended on at multiple Install all the dependencies, but only allow one version for each package. Verifies that already installed files in node_modules did not get removed. If you want to ensure yarn.lock is not updated, use -frozen-lockfile. If yarn.lock is absent, or is not enough to satisfy all the dependencies listed in package.json (for example, if you manually add a dependency to package.json), Yarn looks for the newest versions available that satisfy the constraints in package.json.If yarn.lock is present and is enough to satisfy all the dependencies listed in package.json, the exact versions recorded in yarn.lock are installed, and yarn.lock will be unchanged.The yarn.lock file is utilized as follows: Install all the dependencies listed within package.json in the local If you need reproducible dependencies, which is usually the case with the continuous integration systems, you should pass -frozen-lockfile flag. Running yarn with no command will run yarn install, passing through any provided flags. These have been replaced by yarn add and yarn add -dev. If you are used to using npm you might be expecting to use -save or This is mostĬommonly used when you have just checked out code for a project, or whenĪnother developer on the project has added a new dependency that you need to Yarn install is used to install all dependencies for a project.

Npm save dependencies to package.json