Set MYPY_CONFIG_FILE_DIR environment variable

[blueyed]

In addition to / as an alternative to #7967 mypy could set an environment variable of the config file being used.

This could be used with e.g. mypy_path then (mypy_path = $MYPY_CONFIGFILE/src), and also with defaults like cache_dir.

[JukkaL]

I like this better than #7967, since this preserves backward compatibility. My proposal for the name of the variable is MYPY_CONFIG_FILE_DIR.

[mridullpandey]

hi @blueyed i want work on it will you please elaborate it

[blueyed]

@mridullpandey
What is unclear here?
It should set MYPY_CONFIG_FILE_DIR in os.environ, so that it can be expanded / is available while parsing the config.

[blueyed]

btw: I think $MYPY_CONFIG_FILE(_PATH) might be more flexible: it would provide the actual file (which might be mypy.ini, setup.cfg etc), and could also be used as $MYPY_CONFIG_FILE/../… to have its directory then.
While $MYPY_CONFIG_FILE_DIR might be more explicit, we might end up with adding $MYPY_CONFIG_FILE_PATH additionally afterwards.

[JukkaL]

@blueyed Do you have a use case for using the path to the config file, instead of the directory where it's located? Using .. after a path to a file looks odd to me (though it's not hard to support), and I'd rather avoid it.

@mridullpandey Config file parsing is implemented in mypy.config_parser. In particular, expand_path seems relevant.

[blueyed]

@JukkaL
Not really, but thought about it when adding PYTEST_CONFIG_{FILE,DIR} to pytest, and figured it might be more flexible, since you cannot determine the ini file being used from the dir (due to different names).
As for pytest I've thought that processes/tests being run by pytest then might be able to get the used config file location, but have not thought much about a use case.

$file/.. is a bit weird, but gets resolved fine via os.path.{normpath,realpath}.

So I am +0 myself on using the file - mainly to avoid having to add another env var later, and given that it is more explicit/precise. But it has the downside of having to append "/.." for the more typical use case (this issue).

[joybh98]

i'm taking this issue