For a quick & dirty look, I did `git grep test`. In there, I noticed circle.yml in the root directory, which I'm guessing is for testing on Circle CI. From th

For a quick & dirty look, I did `git grep test`. In there, I noticed circle.yml in the root directory, which I'm guessing is for testing on Circle CI. From this... https://github.com/stimulusjs/stimulus/blob/master/circle.yml https://github.com/stimulusjs/stimulus/blob/master/circle.ym... Until you have a better idea of how to proceed, try this: $ curl -o- -L https://yarnpkg.com/install.sh https://yarnpkg.com/install.sh | bash $ yarn $ yarn test I'm completely guessing here. I've never used Yarn before just now, but I suspect you'll find some of your answers in there.