CODEWITHSUNDEEP
pythonunit-testingmockingpytest
CaMMelo
CaMMelo

Reputation: 143

How to assert that method has been called with expected data?

I have the following code:

class CreateProfile:
    def __init__(self, profile_repository):
        self.profile_repository = profile_repository

    def __call__(self, create_profile_request):
        if self.profile_repository.exists_by_user_id(create_profile_request.user_id):
            raise ProfileAlreadyExists(create_profile_request.user_id)
        profile = Profile(create_profile_request.user_id, None, None, None, None)
        self.profile_repository.create(profile)

tested with the following:

@patch("profile.core.service.create_profile.Profile")
def test_should_create_empty_profile(
    Profile, profile_repository, create_profile_request, service
):
    profile = ProfileFactory(user_id=sentinel.profile_id)
    Profile.return_value = profile
    service(create_profile_request)
    profile_repository.create.assert_called_with(profile)
    assert sentinel.profile_id == profile.id
    assert None is profile.name
    assert None is profile.nick
    assert None is profile.bio
    assert None is profile.status

the problem is that if a make the following change to the code, the test will still be green.

class CreateProfile:
    def __init__(self, profile_repository):
        self.profile_repository = profile_repository

    def __call__(self, create_profile_request):
        if self.profile_repository.exists_by_user_id(create_profile_request.user_id):
            raise ProfileAlreadyExists(create_profile_request.user_id)
        profile = Profile(create_profile_request.user_id, None, None, None, None)
        id = profile.id
        profile.id = None
        self.profile_repository.create(profile)
        profile = id

Although this change is kinda dumb to be done and therefore not expected to happen, I feel like I am missing something in the test case because I cannot be sure that the data that I sent to the repository is correct at the moment it has been called. I once wrote a piece of code that would store a copy of the arguments and made method mock side_effect to execute it and later check the data that has been stored but it seems like something that someone would already have done and as I did not found anything beeing done like this I am stuck with the following question:

Should I be testing this? And if yes, how can I do it correctly?

Upvotes: 0

Views: 298

Answers (1)

Bernstern
Bernstern

Reputation: 201

I would recommend looking into mocking the call that you are trying to do and levering the assert_called_with functionality.

I would highly recommend this video for getting familiar with the patch function and mocks as a whole.

Upvotes: 2

Related Questions