Feature request - Add tab completion for test classes and functions

[timhoffm]

Pytest can tab-complete for running individual files

pytest path_to/test_file.py

It would be great to extend the completion to classes and functions

pytest path_to/test_file.py::test_function

pytest path_to/test_file.py::TestClass::test_method

AFAICS it should be relatively straight forward to extend FastFilesCompleter for that. I may get around implemting this at some point.
Question: would it be ok for the completer to import the test_file.py or should we parse the contents via AST?

[nicoddemus]

Hi @timhoffm!

I think AST should be preferred, as importing files always has the chance of executing side-effects. 👍

[RonnyPfannschmidt]

Without import we can only handle simple cases

[nicoddemus]

Indeed, tests generated at runtime would not be found then.

[timhoffm]

From my experience, generated tests are a niche application, but YMMV. It would not be the end of the world if tab completion cannot find them 😄.

OTOH pytest will import the modules for test discovery. Side effects will be run then anyway. The only reason I see for not import for completion would be that such side effects could be slow and thus slow down the completer.

[RonnyPfannschmidt]

for tab completion i would propose to simply import and collect once
also gies a good reason to make collection performance better

[bhrutledge]

Could this be related to #5514?

Also, possibly related: I've pondered how to select tests to run via fuzzy autocompletion, maybe building on fzf. I think that would require a cache of collected tests. Without looking at the current autocomplete implementation, I wonder if that cache could be useful for this issue as well.

[timhoffm]

Yes, this is essentially the same as #5514.

[dbaty]

I've pondered how to select tests to run via fuzzy autocompletion, maybe building on fzf.

@bhrutledge : for what it's worth, I wrote a small program (brilliantly named testfinder) that helps me do that. Basically, it parses all Python test files and prints pytest-compatible "paths" for all test classes, methods and functions. You can then feed that to fzf and voilà, you have fzf-powered auto-completion for pytest. It's a bit rough (using regexps, not reading the AST) but it works well enough. :)