As tuleap developpers,
We want to have a strict CI job that enforces javascript coding style
So that we spend less time doing back-and-forth with styling issues in Code review.
We also want prettier to be as up-to-date as possible.

To that end, we need the CI to just run a simple command and check if there are git diffs.
As the Tuleap Javascript codebase has 10x fewer lines than its PHP codebase, it is still acceptable to format it entirely.