Test CRLF vs LF in files (file is modified even though it's "not modified" and can't `git checkout -- .`)

Sometimes files that use CRLF instead of LF get's merged into the repo and this breaks all the things. Need a test for it.
My naive attempt at a test looked like this, but fails since the docker-image doesn't have file installed (oddly enough)

crlf:
  stage: build
  script:
    - ! find . -name "*.md" -not -type d -exec file "{}" ";" | grep CRLF

This "bug" results in things like this 38408535 being merged leaving everyones local git-repo in a broken state (can't pull/checkout because of dirty repo) even when fixed on master

If anyone ends up in this state. (Assuming you are on the master branch)

git add the-broken-file
git commit -m "throw away"
git pull origin master
git checkout --soft origin/master

You should now be fine 🙄