Python, mock: raise exception [closed]
I'm having issues raising an exception from a function in my test:
### Implemetation
def MethodToTest():
myVar = StdObject()
try:
myVar.raiseError() # <--- here
return True
except Exception as e:
# ... code to test
return False
### Test file
@patch('stdLib.StdObject', autospec=True)
def test_MethodeToTest(self, mockedObjectConstructor):
mockedObj = mockedObjectConstructor.return_value
mockedObj.raiseError.side_effect = Exception('Test') # <--- do not work
ret = MethodToTest()
assert ret is False
I would like to raiseError()
function to raise an error.
I found several examples on SO, but none that matched my need.
I changed
@patch('stdLib.StdObject', autospec=True)
to
@patch('stdLib.StdObject', **{'return_value.raiseError.side_effect': Exception()})
and removed the # <--- do not work
line.
It's now working.
This is a good example.
EDIT:
mockedObj.raiseError.side_effect = Mock(side_effect=Exception('Test'))
also works.
Ok, your answer you provided is valid, but you changed how you did it (which is fine. To fix your original problem, you need to assign a function to side_effect, not the results or an object:
def my_side_effect():
raise Exception("Test")
@patch('stdLib.StdObject', autospec=True)
def test_MethodeToTest(self, mockedObjectConstructor):
mockedObj = mockedObjectConstructor.return_value
mockedObj.raiseError.side_effect = my_side_effect # <- note no brackets,
ret = MethodToTest()
assert ret is False
Hope that helps. Note, if the target method takes args, the side effect needs to take args as well (I believe).