Personally, I would never run a linter of any kind on a full codebase that doesn't have tests. After having been bitten by all kinds of bugs over the years, I wouldn't suggest auto-linting any file that you aren't actively working on.

It's rare that linting will actually make the code work better. Granted, it could catch some security bugs. But they can - and will - introduce new bugs. You just have to ask if it's worth the risk.