Mirror codebase structure in tests

[ricardoV94]

Discussed in #5579

^{Originally posted by ricardoV94 March 11, 2022}
I think the tests files should mirror the original codebase. So they should be in a file with the same name as where the functions/classes that it tests are defined. E.g.,, timeseries tests should be in tests/distributions/test_timeseries.py. This is how Aesara does it and its much easier to find what tests relate to what code, and also to spot gaps in our tests.

Originally posted by @ricardoV94 in #5298 (comment)

This would also allow to break up the immensely large and slow test_distributions.py, which was already brought up in #5410 (comment)

Also, #5577 (comment)

[Armavica]

What would you think to also move tests out of pymc? I think that it is the standard practice: ref 1, ref 2. This typically allows to grep for something in the code while avoiding plenty of matches from the tests, something which I do often.

[ricardoV94]

What would you think to also move tests out of pymc? I think that it is the standard practice: ref 1, ref 2. This typically allows to grep for something in the code while avoiding plenty of matches from the tests, something which I do often.

I have no idea. Any downsides to that?

[Armavica]

I can't see any. Aesara also has their tests outside of the code directory.

[ricardoV94]

@Armavica do you want to open a discussion for moving the tests out of pymc?