using pytest.raises to catch expected custom error
pytest, python
Solution
What is stopping you importing the specific exception and using it in your `with` pytest.raises statement? Why is this not working? It would be more helpful if you could provide more detail about what problem you are facing.
# your code
class CustomError(Exception):
pass
def foo():
raise ValueError('everything is broken')
def bar():
raise CustomError('still broken')
#############
# your test
import pytest
# import your module, or functions from it, incl. exception class
def test_fooErrorHandling():
with pytest.raises(ValueError) as excinfo:
foo()
assert excinfo.value.message == 'everything is broken'
def test_barSimpleErrorHandling():
# don't care about the specific message
with pytest.raises(CustomError):
bar()
def test_barSpecificErrorHandling():
# check the specific error message
with pytest.raises(MyErr) as excinfo:
bar()
assert excinfo.value.message == 'oh no!'
def test_barWithoutImportingExceptionClass():
# if for some reason you can't import the specific exception class,
# catch it as generic and verify it's in the str(excinfo)
with pytest.raises(Exception) as excinfo:
bar()
assert 'MyErr:' in str(excinfo)
Problem
I am new to `pytest` and am trying to convert some functional test scripts into ones that play nicely with `pytest`. My module has custom error types and I'm trying to use the `with pytest.raises() as excinfo` method. This is a scientific/numerical package and I need to test that certain methods are consistent when called, so I can't just drill down to the lower-level stuff.