LIVE / pybind11 /tests /test_exceptions.py
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# -*- coding: utf-8 -*-
import sys
import pytest
from pybind11_tests import exceptions as m
import pybind11_cross_module_tests as cm
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_cross_module_exceptions():
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()
def test_python_call_in_catch():
d = {}
assert m.python_call_in_destructor(d) is True
assert d["good"] is True
def test_python_alreadyset_in_destructor(monkeypatch, capsys):
hooked = False
triggered = [False] # mutable, so Python 2.7 closure can modify it
if hasattr(sys, 'unraisablehook'): # Python 3.8+
hooked = True
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':
triggered[0] = 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[0] is True
_, captured_stderr = capsys.readouterr()
# Error message is different in Python 2 and 3, check for words that appear in both
assert 'ignored' in captured_stderr and 'already_set demo' in captured_stderr
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"
# This can often happen if you wrap a pybind11 class in a Python wrapper
def test_invalid_repr():
class MyRepr(object):
def __repr__(self):
raise AttributeError("Example error")
with pytest.raises(TypeError):
m.simple_bool_passthrough(MyRepr())