[merksoftworks]

I'd like to experiment with writing a reflection based dynamic type annotator for one of these. Just as a toy. Imagine a module which monkey patches every function, class in the parent module it is loaded into, then reflects on the arguments at run time slowly building up a database of expected type signatures. The user would then pick through the deltas approving what made sense.

[LoganDark]

This is a neat idea, but for large systems it could take a long time to fully exercise every code path with all possible input data. (If this sounds way too excessive, that's because normal people don't do this.)

Unless you mean something like record prod for a few weeks to months, similar to how Netflix uses eBPF (except they run it all the time).

[merksoftworks]

I think my main use case would be to run it on unit tests, and then to provide a human-in-the-loop way to slowly hydrate small to medium sized code bases with types. Maybe progressive refactor tools aren't something anyone actually wants to use or maintain, because I just don't see them around that much.