pybind11/tests/test_exceptions.py

273 lines
8.7 KiB
Python

import sys
import pytest
import env
import pybind11_cross_module_tests as cm
from pybind11_tests import exceptions as m
def test_std_exception(msg):
with pytest.raises(RuntimeError) as excinfo:
m.throw_std_exception()
assert msg(excinfo.value) == "This exception was intentionally thrown."
def test_error_already_set(msg):
with pytest.raises(RuntimeError) as excinfo:
m.throw_already_set(False)
assert msg(excinfo.value) == "Unknown internal error occurred"
with pytest.raises(ValueError) as excinfo:
m.throw_already_set(True)
assert msg(excinfo.value) == "foo"
def test_raise_from(msg):
with pytest.raises(ValueError) as excinfo:
m.raise_from()
assert msg(excinfo.value) == "outer"
assert msg(excinfo.value.__cause__) == "inner"
def test_raise_from_already_set(msg):
with pytest.raises(ValueError) as excinfo:
m.raise_from_already_set()
assert msg(excinfo.value) == "outer"
assert msg(excinfo.value.__cause__) == "inner"
def test_cross_module_exceptions(msg):
with pytest.raises(RuntimeError) as excinfo:
cm.raise_runtime_error()
assert str(excinfo.value) == "My runtime error"
with pytest.raises(ValueError) as excinfo:
cm.raise_value_error()
assert str(excinfo.value) == "My value error"
with pytest.raises(ValueError) as excinfo:
cm.throw_pybind_value_error()
assert str(excinfo.value) == "pybind11 value error"
with pytest.raises(TypeError) as excinfo:
cm.throw_pybind_type_error()
assert str(excinfo.value) == "pybind11 type error"
with pytest.raises(StopIteration) as excinfo:
cm.throw_stop_iteration()
with pytest.raises(cm.LocalSimpleException) as excinfo:
cm.throw_local_simple_error()
assert msg(excinfo.value) == "external mod"
with pytest.raises(KeyError) as excinfo:
cm.throw_local_error()
# KeyError is a repr of the key, so it has an extra set of quotes
assert str(excinfo.value) == "'just local'"
# TODO: FIXME
@pytest.mark.xfail(
"env.PYPY and env.MACOS",
raises=RuntimeError,
reason="Expected failure with PyPy and libc++ (Issue #2847 & PR #2999)",
)
def test_cross_module_exception_translator():
with pytest.raises(KeyError):
# translator registered in cross_module_tests
m.throw_should_be_translated_to_key_error()
def test_python_call_in_catch():
d = {}
assert m.python_call_in_destructor(d) is True
assert d["good"] is True
def ignore_pytest_unraisable_warning(f):
unraisable = "PytestUnraisableExceptionWarning"
if hasattr(pytest, unraisable): # Python >= 3.8 and pytest >= 6
dec = pytest.mark.filterwarnings(f"ignore::pytest.{unraisable}")
return dec(f)
else:
return f
# TODO: find out why this fails on PyPy, https://foss.heptapod.net/pypy/pypy/-/issues/3583
@pytest.mark.xfail(env.PYPY, reason="Failure on PyPy 3.8 (7.3.7)", strict=False)
@ignore_pytest_unraisable_warning
def test_python_alreadyset_in_destructor(monkeypatch, capsys):
hooked = False
triggered = False
if hasattr(sys, "unraisablehook"): # Python 3.8+
hooked = True
# Don't take `sys.unraisablehook`, as that's overwritten by pytest
default_hook = sys.__unraisablehook__
def hook(unraisable_hook_args):
exc_type, exc_value, exc_tb, err_msg, obj = unraisable_hook_args
if obj == "already_set demo":
nonlocal triggered
triggered = True
default_hook(unraisable_hook_args)
return
# Use monkeypatch so pytest can apply and remove the patch as appropriate
monkeypatch.setattr(sys, "unraisablehook", hook)
assert m.python_alreadyset_in_destructor("already_set demo") is True
if hooked:
assert triggered is True
_, captured_stderr = capsys.readouterr()
assert captured_stderr.startswith("Exception ignored in: 'already_set demo'")
assert captured_stderr.rstrip().endswith("KeyError: 'bar'")
def test_exception_matches():
assert m.exception_matches()
assert m.exception_matches_base()
assert m.modulenotfound_exception_matches_base()
def test_custom(msg):
# Can we catch a MyException?
with pytest.raises(m.MyException) as excinfo:
m.throws1()
assert msg(excinfo.value) == "this error should go to a custom type"
# Can we translate to standard Python exceptions?
with pytest.raises(RuntimeError) as excinfo:
m.throws2()
assert msg(excinfo.value) == "this error should go to a standard Python exception"
# Can we handle unknown exceptions?
with pytest.raises(RuntimeError) as excinfo:
m.throws3()
assert msg(excinfo.value) == "Caught an unknown exception!"
# Can we delegate to another handler by rethrowing?
with pytest.raises(m.MyException) as excinfo:
m.throws4()
assert msg(excinfo.value) == "this error is rethrown"
# Can we fall-through to the default handler?
with pytest.raises(RuntimeError) as excinfo:
m.throws_logic_error()
assert (
msg(excinfo.value) == "this error should fall through to the standard handler"
)
# OverFlow error translation.
with pytest.raises(OverflowError) as excinfo:
m.throws_overflow_error()
# Can we handle a helper-declared exception?
with pytest.raises(m.MyException5) as excinfo:
m.throws5()
assert msg(excinfo.value) == "this is a helper-defined translated exception"
# Exception subclassing:
with pytest.raises(m.MyException5) as excinfo:
m.throws5_1()
assert msg(excinfo.value) == "MyException5 subclass"
assert isinstance(excinfo.value, m.MyException5_1)
with pytest.raises(m.MyException5_1) as excinfo:
m.throws5_1()
assert msg(excinfo.value) == "MyException5 subclass"
with pytest.raises(m.MyException5) as excinfo:
try:
m.throws5()
except m.MyException5_1:
raise RuntimeError("Exception error: caught child from parent")
assert msg(excinfo.value) == "this is a helper-defined translated exception"
def test_nested_throws(capture):
"""Tests nested (e.g. C++ -> Python -> C++) exception handling"""
def throw_myex():
raise m.MyException("nested error")
def throw_myex5():
raise m.MyException5("nested error 5")
# In the comments below, the exception is caught in the first step, thrown in the last step
# C++ -> Python
with capture:
m.try_catch(m.MyException5, throw_myex5)
assert str(capture).startswith("MyException5: nested error 5")
# Python -> C++ -> Python
with pytest.raises(m.MyException) as excinfo:
m.try_catch(m.MyException5, throw_myex)
assert str(excinfo.value) == "nested error"
def pycatch(exctype, f, *args):
try:
f(*args)
except m.MyException as e:
print(e)
# C++ -> Python -> C++ -> Python
with capture:
m.try_catch(
m.MyException5,
pycatch,
m.MyException,
m.try_catch,
m.MyException,
throw_myex5,
)
assert str(capture).startswith("MyException5: nested error 5")
# C++ -> Python -> C++
with capture:
m.try_catch(m.MyException, pycatch, m.MyException5, m.throws4)
assert capture == "this error is rethrown"
# Python -> C++ -> Python -> C++
with pytest.raises(m.MyException5) as excinfo:
m.try_catch(m.MyException, pycatch, m.MyException, m.throws5)
assert str(excinfo.value) == "this is a helper-defined translated exception"
def test_throw_nested_exception():
with pytest.raises(RuntimeError) as excinfo:
m.throw_nested_exception()
assert str(excinfo.value) == "Outer Exception"
assert str(excinfo.value.__cause__) == "Inner Exception"
# This can often happen if you wrap a pybind11 class in a Python wrapper
def test_invalid_repr():
class MyRepr:
def __repr__(self):
raise AttributeError("Example error")
with pytest.raises(TypeError):
m.simple_bool_passthrough(MyRepr())
def test_local_translator(msg):
"""Tests that a local translator works and that the local translator from
the cross module is not applied"""
with pytest.raises(RuntimeError) as excinfo:
m.throws6()
assert msg(excinfo.value) == "MyException6 only handled in this module"
with pytest.raises(RuntimeError) as excinfo:
m.throws_local_error()
assert not isinstance(excinfo.value, KeyError)
assert msg(excinfo.value) == "never caught"
with pytest.raises(Exception) as excinfo:
m.throws_local_simple_error()
assert not isinstance(excinfo.value, cm.LocalSimpleException)
assert msg(excinfo.value) == "this mod"