Convert a project from npm to yarn

At a client, we’re converting all projects (i.e., sites, services, libraries) from npm to yarn. Mostly for the speed (as it uses the internal cache).

Step by step guide

Install yarn in your local environment * https://yarnpkg.com/lang/en/docs/install/
Run yarn install * This will create a yarn.lock file * Add that file to the repo: git add yarn.lock
Modify Dockerfile * Install yarn (in the Dockerfile). Idea: shortcut this execution with yarn --version in case it is installed * Configure the PATH variable (ENV PATH …) * ADD yarn.lock * Replace npm install with yarn install
Modify pipeline * See example (below) * install_yarn. Idea: shortcut this execution with yarn --version in case it is installed * Replace npm install with yarn install
Test it

Jenkins

Build step: execute shell

function install_yarn {
  yarn --version || curl -o- -L https://yarnpkg.com/install.sh | bash
  export PATH="$HOME/.yarn/bin:$PATH"
}

install_yarn

yarn install