mypy: Fix erroring files.

[roberthoenig]

Background

We have recently added mypy support to this repo, but many files are corrupted and throw errors on mypy.

Task

#126 updates the exclude_list in tools/run-mypy Each file in this list errors on mypy. We should fix each file and remove it from the list. zulip_bots/zulip_bots/bots is an exception, we don't enforce mypy annotations in this directory.

This task is great for beginners or/and those who want to get comfortable with mypy annotations.

[alenavolk]

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[alenavolk]

@derAnfaenger There's a bunch of files on that list that don't cause errors in my case (I tried removing them and running ./tools/run-mypy):

zulip/integrations/git/zulip_git_config.py
zulip/integrations/irc/irc_mirror_backend.py
zulip/integrations/perforce/zulip_perforce_config.py
zulip/integrations/perforce/git_p4.py
zulip/integrations/svn/zulip_svn_config.py
zulip/tests/__init__.py
zulip_botserver/tests/__init__.py
zulip_botserver/zulip_botserver/server.py

Could this be because mypy works differently with different Python versions? I use Python 3.6.

[roberthoenig]

Possible. We have a fixed version of mypy in the virtualenv that should work the same for everybody, are you using that one (0.521)?

[alenavolk]

@derAnfaenger Yep.

[alenavolk]

@derAnfaenger Do these files still cause errors if you run ./tools/run-mypy without excluding them? If so, could you specify what version of Python you have?

[roberthoenig]

Hrmm, this is strange: zulip_git_config.py contains no annotations at all and should therefore be caught by --disallow-untyped-defs, but it doesn't. Adding --disallow-untyped-calls as an argument catches the file, but also a bunch of other files not yet in the exclusion list.

I'd say that you should feel free to remove the files not caught by mypy, since there hasn't been any breaking change to run-mypy.

[alenavolk]

@derAnfaenger Hm, interesting. I'll focus on the rest of the files then. Thanks for the feedback!

[alenavolk]

Just a quick update. I managed to reproduce the errors from all excluded files by deleting the .mypy_cache dir from the project root.