Imo the issue here is the assumption that test helpers are code only used in tests. For a library I don’t think that’s an assumption, that should be made and therefore I actually support the existing approaches of having those modules be handled just like any other.
There are some valid concerns like file size bloat, but those are optimizations and also likely most relevant in really constraint environments, where you’d have the same concern not only about modules holding test helpers, but rather any module. So for the file size concern it makes sense to use a wholistic approach of dealing with it, rather than thinking about those handful of modules specific to test helpers.
