Given a test like:
```py
@pytest.mark.parametrize("a,b", [("b", "c"), ("c", "d")])
def test_a(a, b):
assert False
```
This modifies the diagnostic message from:
```
neotest: assert False
neotest: assert False
```
to:
```
neotest: [b-c] assert False
neotest: [c-d] assert False
```
This is the same internal value which `pytest` uses for parametrized
instances in its output, so it should be fully consistent.
Without this, the diagnostic messages aren't very useful for
parametrized tests: you can't identify _which_ of the multiple test
which execute the given line are failing.
Fixes: #30
* include type of unhandled pytest exc_repr in error message
This makes triage of such issues a little simpler.
* pytest: expect the more general ExceptionRepr class
This is the (abstract) supertype of the currently-used
ExceptionChainRepr, and defines all of the attributes currently used by
the code.
(This changes results in sensible output for `ReprExceptionInfo`
instances, which is what my pytest invocations were generating.)
* pytest: use pytest_runtest_makereport for consistent exception handling
The `report` passed to `pytest_runtest_logreport` has a different
internal exception representation depending on the `--tb` option with
which `pytest` is configured: some of these representations do not
include the traceback frames to allow us to calculate line numbers.
`pytest_runtest_makereport`, however, has access to the original
`ExceptionInfo` object when an exception is raised: this commit switches
to using a `pytest_runtest_makereport` hookwrapper, so we can access the
pytest-generated report as before, but get exception handling
independent of `--tb` setting.
Fixes: #28
When running neotest with the DAP strategy (nvim-dap), e.g.
require("neotest").run.run({ strategy = "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.
Having `NeotestResultCollector` (a pytest plugin) as a inner local
class would make the code a bit difficult to read due to quite much
indentation. This commit does refactoring on NeotestResultCollector
to make it a module-level class with a reference to NeotestAdapter.
This refactoring would make easier adding more pytest plugins
(e.g., debugger integration) in the future.
There should be no changes in behaviors.
