pytest mock example

requirements.txt

pytest
pytest-mock

test_thing.py

import pytest
import thing

@pytest.fixture()
def event():
    return {}

def test_exposure_simple_function(event):
    assert thing.simple_function() == "You have called simple_function"

def test_mock(mocker):
    mocker.patch('exposure.simple_function')
    thing.simple_function.return_value = "You have mocked simple_function"
    assert thing.simple_function() == "You have mocked simple_function"

thing.py

def simple_function():
    return "You have called simple_function"