Allow dimension-checking of multiple return values

[db434]

Extend the @returns decorator so it can handle functions with multiple return values.

Example:

>>> @returns(length, length/time**2)
... def f(a, v):
...     return a * v, v / a
...
>>> res = f(a= 2 * u.s, v = 3 * u.m/u.s)
>>> print(*res)
6 m 1.5 m/s**2

I think I've followed everything in CONTRIBUTING, but please let me know if I've missed anything.

[neutrinoceros]

This seems like a good idea ! I don't have time to review in detail right now but I'll be back very shortly. In the mean time, I suggest updating this decorator's documentation to reflect the new possibility. Thanks for your work !

[db434]

Thanks for taking a look.

In the mean time, I suggest updating this decorator's documentation to reflect the new possibility.

I think I've done this already - is there anywhere else that you would suggest changing?

[neutrinoceros]

You've updated the docstring (that's great !), but I'm talking about the narrative documentation. Namely, I'd expect some update to docs/usage.rst

[neutrinoceros]

Thank you for following through ! automated testing seems to have caught some syntax error in the docs. I suggest you try to run tox locally to make sure everything is okay, because currently we need to manually approve your tests to run every time you push (this is a security measure against bad agents, it only applies to new contributors !).

[db434]

Sorry for this CI spam - I've struggled to get all of the tests running locally. Hopefully this is the last time..!

[neutrinoceros]

This looks great ! thank you so much for working on this and adding tests ! I found a subtle way your change can break backward compatibility for some users, and provided some indications on how to avoid that. Don't hesitate if you have any questions about that

[neutrinoceros]

Awesome job ! The only missing part I can think of would be a couple tests that the deprecated API behaves as expected, but I've tested it manually and I'd be okay to take the PR as is and add the tests later. I'll defer merging for a week or two so as to give other maintainers a chance to weigh in.

[db434]

I believe those tests are here. Is there anything else you're looking for?

Thanks for your patience with this!

[neutrinoceros]

Oh I somehow missed them, even better ! I have no further request.