Basic Python and Java testing and running issues

[SweetTalkingBaby]

Hello everybody! I'm brand new to Pants and have mostly managed to get it going thanks to the documentation, except for a couple of things. Please see this basic repo (initial commit 2e6c976) with Python and Java code.

Three issues:

1. Upon pants test ::, the Java tests all pass, but Pytest fails to identify any of the Python tests.
2. pants package src/python/app/line_printer:lp creates the lp.pex binary, but pants run src/python/app/line_printer:lp yields ImportError: Error while finding module specification for 'app.line_printer'.
3. pants package src/java/app/lineprinter:lp creates the lp.jar file, but pants run src/java/app/lineprinter:lp yields java.lang.ClassNotFoundException: app.lineprinter.Main.

Any advice would be greatly appreciated!

[benjyw]

Pants is working as intended. Your issue is that your python tests contain no test functions. Pytest expects test functions to start with test_, yours end with _test. If you rename them you will see your tests run.

[benjyw]

Or there is probably pytest config to change the test discovery pattern, but again that is a pytest thing, not a Pants thing.

[SweetTalkingBaby]

For completeness, the immediate solutions were:

1. The Python test functions need to begin with test_ in order for Pytest to recognise them.
2. Changed the entry_point of pex_binary in the Python app BUILD file to refer to the function.
3. Added an explicit dependency :lineprinter to the deploy_jar in the Java app BUILD file.

But I've made a few other changes, which required adding an explicit dependency :line_printer to pex_binary too (commit b79f589). Now you can run the apps (which now take arguments) with pants run src/python/app/line_printer:lp -- 2 3 4 and pants run src/java/app/lineprinter:lp -- 2 3 4.