Description

Stub packages, modules and attributes.

This pytest plugin allows you to replace dependencies with stubs.

It can be useful if you want to test some code using a dependency without actually having this dependency, for example if you’re testing your library, which uses some parts of another library.

Requirements

• Python 3.6+

• pytest >= 2.9.0

How to use

You can stub dependencies either with your own custom objects or you may instruct pytest-stub to generate functions or classes for you. Use stub fixture in your test functions, like this:

def test_django_related(stub):

    stub.apply({
        # Replace `call_command` with a generated function.
        'django.core.management.call_command': '[func]',

        # Replace `BaseCommand` with a generated class.
        'django.core.management.base.BaseCommand': '[cls]',

        # Replace `dummy` with generated MagicMock.
        'django.dummy': '[mock]',

        # Replace entire `cv2` module.
        'cv2': '[mock]',

        # Sometimes we need just a persistent (always the same) magic mock.
        'numpy': '[mock_persist]',

        # Stub multiple attributes in the same module with custom objects.
        'django.conf': {
            'settings': object(),
            'some': True,
        },

    })

If we want to replace some dependency with a stub not in a fixture but globally, we can use stub_global() function in root conftest.py (this code will apply patch before tests, so tests will be safe to import code using dependencies).

from pytest_stub.toolbox import stub_global

stub_global({
    'cv2': '[mock_persist]',
})