Dependency on `ppx_expect`?

[mbarbin]

The main opam package declares a dependency on ppx_expect.

Arguably this would be better if the lib itself didn't impose this transitive dependency.

I'm not sure whether this is a typo or if it is indeed used in non-testing code (I haven't checked).

[charlesetc]

It's not used by the non-testing code except the tests are indeed in the main .ml file. This is probably less than ideal and I would land a PR moving them to remove the ppx_expect dependency.

[mbarbin]

Hi @charlesetc ! Nice to hear from you.

It's been a while, but I just tried to build the project with a recent env and there seems to be several things needed to fix deprecated messages, etc. I suppose one thing we could do to maintain high compatibility for the lib itself, but allow to modernize the tests, would be to create a separate top level packages for the tests (e.g. feather_tests) - the goal would be that this package could have stricter lower bounds deps and be only checked with more recent dependencies. We would keep the expect-test dep for that package and remove it from the core one.

If you'd like I could explore something along these lines at one point when I get a moment to contribute. Cheers!

[charlesetc]

Good to hear from you too!

Thanks for taking a look — that sounds like a great plan, I'd happily review & land anything modernizing it. Cheers!

[mbarbin]

I'll try to avoid changing the lower bounds if possible but maybe if this is too complicated, I suspect I may end up suggesting dropping the support strictly below ocaml 4.14 and base & co v0.16. Below that honestly I am not sure if the tradeoff is worth it.

[charlesetc]

Sure that sounds good to me!