I wish there was a warning for unused code. Currently if you have unused code covered by tests, it won’t be considered unused. So there is a good chance you forget to remove it during refactoring.
I’d love the compiler to warn me about unused code ignoring test calls. For the code that needs to be unused on purpose (e.g. to be called manually via console, or specifically for tests) there could be a special tag to suppress compiler warnings.
It doesn’t seem like it was ever actually published on hex. Also it doesn’t seem to support Elixir 1.10 yet, although the PR to support that looks like it is mostly complete