Hi folks,

In this post I talk about a nice way to mock functions when developing Python applications and using Pytest.

There are many ways of doing mocking in Python. But in this post I will cover how to do it using a nice library called pytest-mock.

To use pytest-mock, you need to install it using a command

pip install pytest-mock

Say you want to mock a function called is_eligible inside a module called application. You just need to use the mocker fixture which is provided by pytest-mock.

So your function can look as follows.

def test_some_function(mocker):
    mocker.patch('application.is_eligible', return_value=True)
    assert some_func_using_is_eligible() == True

That’s all for now. Till next time, happy software development.

References

Mocking functions in Python with Pytest Part I. https://www.freblogg.com/pytest-functions-mocking-1