testing help

[michelkluger]

I am using a CachedSession and its method get, for an external endpoint,

in my test this endpoint is not reached, so I want to mock the response.

which I am trying to do with,

mock_cached_session.get.return_value.status_code = 200

mock_cached_session.get.return_value.json.return_value = [dict(mock_response)]
but after mocking, I am trying to test that caching time is respected, which it is when I manually test it, but not when testing.

I the mock negatively impacting the caching? how can I write such test?

[JWCook]

Are you mocking CachedSession.get? If so, that completely replaces that method with a Mock object, so there won't be any caching. There are a few options to use both mocking and caching:

• Mock requests.Session.send(). You can do this using patch.object(). You may need to add a few attributes to the return value so it behaves like a requests.Response object.
• Use a dedicated request mocking library. There are a few extra steps to take here, since both requests-cache and the mocking library will modify or extend requests.Session. There are examples in the docs for using both requests-mock and responses. Some minimal tests for these can be found under tests/compat.

[michelkluger]

@JWCook thank you very much, I am a bit beginner in the topic,

I wrote a test snippet,

@pytest.fixture
def patch_times() -> list[datetime]:
TWO_MINUTES = 2 * 60
t0 = datetime.now()
t1 = t0 + timedelta(seconds=TWO_MINUTES)
t2 = t0 + timedelta(seconds=20 * TWO_MINUTES)
patch_times = [t0, t1, t2]
return patch_times

@patch("my_module.CachedSession.get")
def test_cached_session(patch_times: list[datetime]) -> None:
url = "http://test.com"
for patch_time in patch_times:
with patch("time.time", return_value=patch_time.timestamp()):
session = CachedSession()
response = session.get(url)
if patch_time == patch_times[1]:
assert response.from_cache
else:
assert not response.from_cache

this url does not exist, how can I mock the send here? or make this test work without adding another dependency to my project?
Thank you very much for your support <3

[JWCook]

There's an example in the requests-cache tests here of mocking Session.send(). Almost all the other tests use requests-mock (for unit tests) or httpbin (for integration tests).

Is there a reason you don't want to add testing-only dependencies to your project? If you define these separate from your main dependencies, then users of your project won't need to install them, only other developers who want to run the test suite. A few examples:

• Poetry: you can use dependency groups like tool.poetry.group.test.dependencies
• PDM: you can use tool.pdm.dev-dependencies
• Plain setuptools + pip: you can use a separate requirements-dev.txt file

Also, since you're mocking the system time, you might find the time-machine library useful (more info here on how it's different from unittest.mock.patch()).