Support to set env variables with code

[mLetrone]

Hi, thank you for Pytest-env!
Currently, it's only possible to define the env variable inside .toml or .ini files, and that works great.
I think it would be a plus to be able to define these variables via code for IDE integration (go to), which would improve readability and centralize the logic.

I thought of something like this as an API

# conftest.py
class EnvTest(AutoEnvEnum):
      HOME = "~/tmp"
      RUN_ENV = 1

If you think it's a good idea, I would be happy to send a PR

[gaborbernat]

class EnvTest(AutoEnvEnum):
HOME = "~/tmp"
RUN_ENV = 1

At that point why not just use os.environ 🤔

[mLetrone]

Well, that's a good point.
The goal is to set the enum members as env variables using os.environ before pytest inspect the tests files and do all the imports.
The issue might occur when some code need to have some env variables set cause of the import, and it failed during collection.

[gaborbernat]

The goal is to set the enum members as env variables using os.environ before pytest inspect the tests files and do all the imports.

Not really possible. As the imports might be on the lines above this code...

[gaborbernat]

#194 per this should work