Added reporting extras option to setup.py

[jamesbraza]

Description

Today, I was looking at the Report generation docs, and noticed lxml is listed as an additional requirement. I thought it would be nice to add as an extra to mypy's setup.py.

This way, inside a requirements-dev.txt, someone can include mypy[reporting] and have lxml installed.

One thing to note: a comment in setup.py says this:

# When changing this, also update mypy-requirements.txt.

NOTE: I did not update mypy-requirements.txt, as I belive extra requirements don't belong there. This will be up to the PR reviewer if he/she wants to add lxml to mypy-requirements.txt.

NOTE 2: I did not pin lxml. I only tested this to work with lxml==4.7.1.

Test Plan

Here is how I verified my change works.

pip install -e "git+ssh://[email protected]/jamesbraza/mypy.git@reporting#egg=mypy"
pip list

outputs:

Package           Version
----------------- --------------------------------------------------
mypy              0.940+dev.c7ca8e3d2c5a957510e70163c8155f2cd9a3f017
mypy-extensions   0.4.3
pip               21.3.1
setuptools        56.0.0
tomli             2.0.0
typing_extensions 4.0.1

then

pip install -e "git+ssh://[email protected]/jamesbraza/mypy.git@reporting#egg=mypy[reporting]"
pip list

outputs:

Package           Version                                            Editable project location
----------------- -------------------------------------------------- ----------------------------------------
lxml              4.7.1
mypy              0.940+dev.c7ca8e3d2c5a957510e70163c8155f2cd9a3f017 /Users/james.braza/code/mypy/hi/src/mypy
mypy-extensions   0.4.3
pip               21.3.1
setuptools        56.0.0
tomli             2.0.0
typing_extensions 4.0.1

I also ran the tests as documented in CONTRIBUTING.md.

[hauntsaninja]

Thanks, this is useful. Would you mind updating the documentation section you linked to mention the extra?

Also to bikeshed, I think I have a vague preference for calling this [reports] instead of the gerund, but happy with whatever you feel is best.

[jamesbraza]

Would you mind updating the documentation section you linked to mention the extra?

Made the changes in the docs, let me know what you think of the wording.

preference for calling this [reports]

No problem, implemented.

[hauntsaninja]

Thank you!