[simonw]

This is brilliant.

pytest is by far the most productive testing framework I've ever tried, for any language. It's so good that it switched me from treating tests as a necessary chore to actively enjoying writing them.

Using ctypes to exercise a C module like this is brilliant - especially the mechanisms used here to work around segmentation faults.

Reminds me of SQLite, which is written in C but uses TCL for most of its test suite.

[drchickensalad]

How do you add a side effect and still call the original in pytest? This is easy in rspec but everywhere I google people say there's no good way.

For example, you're calling code which internally does Too().bar() and you want to advance your time mock after it's called.

[masklinn]

That… has nothing to do with pytest?

You’d probably use something like `wraps` or `side_effect` in `unittest.mock` to delegate to the original with some extra behaviours.

And / or use freezegun’s tick features, when you’re specifically dealing with time.

[bb88]

Replace the original function with a wrapper that calls the function then does the side effect.

This could effectively be something like a decorator.

As far as mocking time objects, look into pytest.freezegun. You should be able to control the date and time as you move forward.

I was able to mock out the datetime.now() at some point in the past. It wasn't with freezegun...

[simonw]

There are lots of good mocking fixtures available for pytest. I've used this one for clock stuff in the past: https://github.com/adamchainz/time-machine#pytest-plugin