在python中对“FileNotFoundError”进行单元测试

Question

I have the following code and wanted to untitest when the given function raises for "FileNotFoundError

def get_token():
try:
    auth = get_auth() # This function returns auth ,if file exists else throws "FileNotFoundError
except FileNotFoundError: 
    auth= create_auth()
return auth

I am having trouble figuring out how to test the condition where it raises "FileNotFoundError" and doesn't call create_auth.

Any hint would be appreciated

Thanks

Answer 1

In your unit test you'd need to mock the get_auth function and cause it to raise a FileNotFoundError by using the .side_effect attribute:

@mock.patch('path.to.my.file.get_auth')
def test_my_test(self, mock_get_auth):
    mock_get_auth.side_effect = FileNotFoundError

You can then test whether create_auth was actually called:

@mock.patch('path.to.my.file.create_auth')
@mock.patch('path.to.my.file.get_auth')
def test_my_test(self, mock_get_auth, mock_create_auth):
    mock_get_auth.side_effect = FileNotFoundError
    get_token()
    self.assertTrue(mock_create_auth.called)