fix: fix stub merging for single-file packages

[tlambert03]

closes #77

pyi stub files were not being detected and merged in two cases:

1. single-module packages, where a .pyi file is also distributed and present in site-packages
2. top module __init__.pyi. This is probably more common than the first case.

[pawamoy]

Same comment as on your other PR: will do my best to review soon, and thank you for your work!

[tlambert03]

don't hurry on my behalf! I know exactly how it goes :)

[tlambert03]

ok, I moved the stub finding logic outside the finder. It will continue to fail to find stubs for which an actual .py file doesn't exist, but will at least eliminate bug that motivated #77 for me.

[pawamoy]

Hey @tlambert03, I'm back 🙂 Busy weeks, sorry.

So, I wanted to try another approach first, and I did, but eventually I like what you did here. I still mixed a bit of both approach, I'll push directly on this PR so you can see, if that's OK with you!

[tlambert03]

Hey @tlambert03, I'm back 🙂 Busy weeks, sorry.

no worries, welcome back :)

I still mixed a bit of both approach, I'll push directly on this PR so you can see, if that's OK with you!

awesome. yes push away!

[pawamoy]

So! I've pushed my changes.

Here's an explanation:

• merged "set members" mixins to bring the same functionality for both modules and collections, without spaghetti code
• in the finder, find_package does all the work of returning the right wrapper Package or NamespacePackage
• Package gained a stubs attribute
• the two previous points allow us to handle top modules along with their stubs, even when submodules=False. I've previously tried to do it differently but it didn't take submodules into account (btw I'm starting to doubt the usefulness of submodules=False...)
• additional test for modules with stubs directly in a search path

[pawamoy]

Let me know what you think! Maybe we could add comments to document the parts that are difficult to understand?

[tlambert03]

Yeah, looks great! I like the changes. This is good by me 👍

[pawamoy]

Great, thank you! I'll merge and cut a new release 🙂