Update mypy config and make it work well with pre-commit

[mathbunnyru]

What I've done:

• Updated mypy config to use --strict --follow-imports error. This makes this tool much more efficient in finding errors.
• Fixed all the errors
• Made pre-commit mypy hook use the same config
• Made sure the pre-commit hook works well and disabled mypy for git commit stage
• Added some inline comments to explain why and how I did it.

[mathbunnyru]

Unfortunately, pre-commit mypy doesn't work the same way as explicit mypy run.
So, it's better to run mypy --config-file ./mypy.ini ./ for now.
CC: @trallard

[consideRatio]

Unfortunately, pre-commit mypy doesn't work the same way as explicit mypy run. So, it's better to run mypy --config-file ./mypy.ini ./ for now.

If we cant use if with pre-commit then that is also relevance to clarify in the file as a comment/fixme preferably linking out to something relevant to track if its to be fixed over time - a github issue in this or upstream repo.

[consideRatio]

Unfortunately, pre-commit mypy doesn't work the same way as explicit mypy run.
So, it's better to run mypy --config-file ./mypy.ini ./ for now.

If it doesn't work the same way, and it's not of importance if we choose way A or B but what is important is that we are consistent, I suggest we stick with anything that can be done with pre-commit instead of sticking with an option that requires manual intervention etc. I've not read up on mypy or what it does though or what difference there are etc.

[mathbunnyru]

@consideRatio thank you for very good suggestions.
I think I made it work well for pre-commit and documented the workaround.
Also I reflected all the changes in the PR message.

Please, take a look and tell me what you think.

[consideRatio]

Beautiful @mathbunnyru! Thanks for being so thorough with the transition to make this code typed, with all this setup I think this repo is really set to maintain typings!!! ❤️ 🎉