Increase test coverage - take 2

[jcugat]

More work towards #316, continuation of #1003

After this is merged, the only remaining untested part will be URLLib3Transport.

Small note about StreamContextManager. The only line not tested is because the only usage of the context manager in an async environment is from BaseClient.stream where it doesn't use the close_client parameter (and by default is false). The only other usage is from the api.stream method but that is always called from a sync context, so the __aexit__ will never have close_client=True. Should it be removed?

[yeraydiazdiaz]

Hey, thanks for your work on this, nice job 💯

The only other usage is from the api.stream method but that is always called from a sync context, so the aexit will never have close_client=True. Should it be removed?

I would say so, seems like dead code.

Left a few suggestions on your comments but in general LGTM 👍

[lovelydinosaur]

Fantastic work, thanks so much!

Going to leave this one with @yeraydiazdiaz since he's got a better handle on it, but tested locally and looking really nice. Will try to help with the follow-up once it's in.

[yeraydiazdiaz]

This looks great. Thanks @jcugat 🚀