added more type hints

[vasdee]

I'm interested in contributing to this project, I was very glad to see that hbmqtt was getting some much needed love :)

I used this opportunity to get familiar with the internals of the code base, but at the same time I found it useful to add more and more type hints as I was exploring. I'm sure there will be some mistakes here and there, some of them were definitely "best guesses".

Just within these added hints alone, it has already high lighted some areas that could already be tightened up, so I think it is definitely worth the effort for adding as much hinting as possible

[FlorianLudwig]

@vasdee thanks! This is awesome.

Looking through it might take some time. Can you have a look at the a filing CI pipeline?

[FlorianLudwig]

Please run mypy amqtt and have a look. Please note that the master branch has 111 errors from mypy and adding more types, makes mypy check more of the code - so the number of errors increased.

You don't have to get the errors down to zero to get this MR into a merge-able territory - just check the mypy output for potential wrong annotations.

[vasdee]

This is about all the type hinting that I can add, and I can't fix all the mypy errors until work is done to remove the excessive use of None
Most of the errors now are because nearly every attribute is an Optional so naturally, accessing an attribute of a None type raises an issue with mypy.

I think this is a good thing, it highlights that cleanup work can be done to make it cleaner :)

[vasdee]

Any progress on getting this merged? I feel it is at a pretty good state and has given me some clean up ideas to further reduce the mypy errors.

[vasdee]

looks like there is some failing tests, which I haven't figured out why they would be failing with type hint additions. This doesn't happen on Master so i'm not sure what is going on..

FAILED tests/test_broker.py::test_client_publish_acl_permitted - asyncio.exceptions.TimeoutError