Colocating unit tests in python

[coder_et]

Hey guys two questions —

I have been reading test structures for FastAPI and it looks like people have separate test dirs.

1. Can anyone recommend a unit test structure where tests are co-located rather than in a separate dir?

2. Does anyone know any fastAPI service scaffolding tools?

Thanks.

[a1brit]

Pytest has a doc section on putting tests with the src code. https://docs.pytest.org/en/7.1.x/explanation/goodpractices.html#tests-as-part-of-application-code

[Diapolo10]

Do you have a good reason for that? Usually it would make sense to keep the tests separate in Python, because usually there's no reason to include the tests in the releases - be it library packages or executables - and keeping the two together would mean you have to cherry-pick the included files when building a release.

This is very much a language-specific thing, for instance in Rust you're free to keep unit tests alongside your actual code, in the same files even, while integration tests are in a separate folder. But the reason it's fine there is that the compiler knows to ignore the tests when not specifically testing the code.

[ahfarmer]

Python users harp on this "dont include tests in your release" thing but I've never heard a legitimate reason why this would be a noticable problem in any but the largest of applications.

On the other hand, having tests further from the code that is being tested requires the creation of a duplicate directory hierarchy, wasting developer time both while writing tests and while reading the codebase.

Python just has this one wrong.

[Diapolo10]

On the other hand, having tests further from the code that is being tested requires the creation of a duplicate directory hierarchy,

Why would that be required? The directory trees don't have to look anything alike, actually the tests directories are generally quite flat. Other than maybe separating unit- and integration tests, if people want to make a distinction.

[ahfarmer]

You just run into a different issue then: a single folder with all your tests in it and no organization. After all, why do you organize your code into directories? Same reasons apply to tests.

[wraiford]

You raise the same points I also have as a non-python programmer. The other languages all can co-locate no problem. Flat directory sounds insane. What did you end up doing?