I have sometimes had a git branch called “tests” because I was adding tests or working on tests. The problem is that many projects have a “tests” directory so if you have a “test” branch, you get this:
$ git diff tests fatal: ambiguous argument 'tests': both revision and filename Use '--' to separate paths from revisions, like this: 'git
[ ...] -- [ ...]'
You can of course use
git diff -- tests and it will work, but it’s easier to just not name a branch “tests” in the first place.