I use “cat -“ so that my code makes more sense to people. I want STDIN declared somehow, and the dash is effective. Technically I shouldn’t have bothered with the cat at all in an HN code snippet, but it was a courtesy to provide a familiar environment for the block I wanted to convey. It worked so well that you linted it! I really appreciate the thought.
also, "cat -" is redundant, use "cat". this behavior is specified by POSIX.