This makes mypy raise an error whenever it detects code which is
statically unreachable, e.g.
x: int
if isinstance(x, str):
... # Statement is unreachable [unreachable]
This is really neat and finds quite a few logic and typing bugs.
Sometimes the code is intentionally unreachable in terms of types, e.g.
raising TypeError when a function is given an argument with a wrong
type. In these cases a `type: ignore[unreachable]` is needed, but I
think it's a nice code hint.
The previous commit made this possible, so utilize it.
Since legacy.py becomes pretty bare, I inlined it into __init__.py. I'm
not sure it's really "legacy" anyway!
Using a simple 50000 items benchmark with `--collect-only -k nomatch`:
Before (two commits ago):
======================== 50000 deselected in 10.31s =====================
19129345 function calls (18275596 primitive calls) in 10.634 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.001 0.001 2.270 2.270 __init__.py:149(pytest_collection_modifyitems)
1 0.036 0.036 2.270 2.270 __init__.py:104(deselect_by_keyword)
50000 0.055 0.000 2.226 0.000 legacy.py:87(matchkeyword)
After:
======================== 50000 deselected in 9.37s =========================
18029363 function calls (17175972 primitive calls) in 9.701 seconds
Ordered by: cumulative time
ncalls tottime percall cumtime percall filename:lineno(function)
1 0.000 0.000 1.394 1.394 __init__.py:239(pytest_collection_modifyitems)
1 0.057 0.057 1.393 1.393 __init__.py:162(deselect_by_keyword)
The matching itself can be optimized more but that's a different story.
Mypy currently is unable to handle assigning attributes on function:
https://github.com/python/mypy/issues/2087.
pytest uses this for the outcome exceptions -- `pytest.fail.Exception`,
`pytest.exit.Exception` etc, and this is the canonical name by which they
are referred.
Initially we started working around this with type: ignores, and later
by switching e.g. `pytest.fail.Exception` with the direct exception
`Failed`. But this causes a lot of churn and is not as nice. And I also
found that some code relies on it, in skipping.py:
def pytest_configure(config):
if config.option.runxfail:
# yay a hack
import pytest
old = pytest.xfail
config._cleanup.append(lambda: setattr(pytest, "xfail", old))
def nop(*args, **kwargs):
pass
nop.Exception = xfail.Exception
setattr(pytest, "xfail", nop)
...
So it seems better to support it. Use a hack to make it work. The rest
of the commit rolls back all of the workarounds we added up to now.
`pytest.raises.Exception` also exists, but it's not used much so I kept
it as-is for now.
Hopefully in the future mypy supports this and this ugliness can be
removed.
ExitCode is used in several internal modules and hooks and so with type
annotations added, needs to be imported a lot.
_pytest.main, being the entry point, generally sits at the top of the
import tree.
So, it's not great to have ExitCode defined in _pytest.main, because it
will cause a lot of import cycles once type annotations are added (in
fact there is already one, which this change removes).
Move it to _pytest.config instead.
_pytest.main still imports ExitCode, so importing from there still
works, although external users should really be importing from `pytest`.
Without restoring the cwd, successive tests might fail to parse the
config (via `_pytest.config._prepareconfig()`, for when `--lsof` is
used).
And it is good practice to restore the cwd in any case anyway.
The current idiom is to use:
assert re.match(pat, result.stdout.str())
Or
assert line in result.stdout.str()
But this does not really give good results when it fails.
Those new functions produce similar output to ther other match lines functions.
