Hello,
The Jenkins slaves had grunt-cli provisioned which is often used by the npm test command. If you get a Jenkins job to fail with:
sh: 1: grunt: not found
Simply add grunt-cli to your project devDependencies and the next build have it installed. Example:
https://gerrit.wikimedia.org/r/#/c/275823/1/package.json,cm
The change removing grunt-cli is: https://gerrit.wikimedia.org/r/#/c/280974/