I basically stopped paying attention to the progress of this feature when it was announced it would use header files. I don't expect I'll use it.
I think it might be worth the headache with libraries - I think type errors are more useful when you cross the boundary into someone else's code. They're still useful within apps, of course, but personally I don't think I hit them often enough to make the headaches of a separate file worthwhile.
My hope is that this is primarily motivated by wanting to maintain backwards compatibility for source, and maybe as more of the ruby ecosystem moves to 3.x future versions will add an alternative way of doing type annotations inline.
I think it might be worth the headache with libraries - I think type errors are more useful when you cross the boundary into someone else's code. They're still useful within apps, of course, but personally I don't think I hit them often enough to make the headaches of a separate file worthwhile.
My hope is that this is primarily motivated by wanting to maintain backwards compatibility for source, and maybe as more of the ruby ecosystem moves to 3.x future versions will add an alternative way of doing type annotations inline.