verify() with timeout

[philipa]

Any plans to support the equivalent of Java's org.mockito.verification.Timeout?

[kaste]

mockito for python is basically community driven. But 'timeout' seems really like an edge user case when you're already using mocks, and I don't think you can brute-force-just-add-it to the current lib bc we have to think about how python usually deals with concurrency.

[philipa]

Thanks.

I find Java mockito very useful when testing callbacks from other threads. Let me give an example.

someAsyncFunction(myMock);
verify(myMock, timeout(30_000)).callback(); 

The Java timeout implementation essentially polls until the condition is satisfied or the timeout expires. It shouldn't be too hard to translate over. If I find I'm missing this a lot, I'll have a go.

FWIW there is a note in the timeout Javadoc: "This feature should be used rarely - figure out a better way of testing your multi-threaded system.". I obviously disagree, although I see the sense of the similar advice for after() since that always waits.

[kaste]

Well, this really depends on how the code actually realizes its asynchronicity. Now, if some_async_fn would be async you could await its result. (In older pythons you converted the thread probably to a Future.)

Otherwise, in python dependency injection is basically optional. If some_async_fn actually is defer_work(partial(fn, myMock)), then you can still mock the otherwise internal, hidden Thread constructor such a fn would call and just ask if the code constructs the Thread correctly and then calls start() on its return value. A second testcase would be if fn calls myMock.callback() during execution.