feat(pytest): exception breakpoints when running with dap strategy

wookayin commented 1 year ago

Implements and Fixes #23.

Summary

When running neotest with the DAP strategy (nvim-dap), we make the pydebug debugger stop at "exception breakpoints" where the exception is thrown out of a pytest method.

This will be very helpful for users to debug failing unit tests.

Tested scenarios

require("neotest").run.run({ strategy = "dap" })

The debugger stops at the lines where the AssertionError was thrown.
When running multiple tests (i.e., test suite: class or module), the debugger will stop multiple times at all the lines where the tests are failing.
Unlike userUnhandled exception breakpoints, it doesn't pause at "handled" exceptions

require("neotest").run.run()

No effects. No interaction with DAP, it should not enter a DAP session.

Notes and/or TODOs

Having the debugger paused at exception breakpoints could be configurable (users may not want it in often cases), via DAP configuration (https://github.com/nvim-neotest/neotest-python/blob/master/lua/neotest-python/init.lua#L19-L36). How should we design an API for providing such options -- probably need to be dealt with in neotest lua API?
Entering a breakpoint is done via a direct communication with debugpy (microsoft/debugpy#1103), but this assumes a specific python DAP adapter; in theory, it could be other DAP adapters. We may need to think about a better way of not breaking the abstraction layers.
When running with a DAP strategy, can we disable the floating window showing neotest output?
Future work: Users may want to run ipdb or pdb instead inside a terminal window (neotest.run.attach) which can be another feature to have in the future.

~Please do not merge yet until #24 is merged.~ #24 is done, rebased.

rcarriga commented 1 year ago

Very nice :grin: Appreciate you investigating the issue and opening a PR! As far as I can see it looks good to go, but I'll need to see it rebased/merged with the merged PR to confirm

wookayin commented 1 year ago

Rebased to origin/master.

Having the debugger paused at exception breakpoints could be configurable

I think this default behavior is just fine, assuming it's desired because users would run it explicitly with { strategy = 'dap' }.

So at this point I do not have anything to add. Feel free to test on your side to see if it works. Any other review comments would be also appreciated.

rcarriga commented 1 year ago

I think this default behavior is just fine, assuming it's desired because users would run it explicitly with { strategy = 'dap' }.

Sorry missed this question, yes I think that makes perfect sense so I'm happy to leave it as is :+1:

No comments from me, appreciate all of the typing and docs! Thanks again :smile:

nvim-neotest / neotest-python