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Comment by StavrosK | Hacker News Reader

I love Hypothesis. I can't find many practical uses for it (it's more useful in more "algorithmic" code, rather than for interactive apps), but it's fantastic in what it does.

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Have you seen the talk I did about using it with Django? http://www.drmaciver.com/2015/06/hypothesis-for-django/

We're all still figuring out the details, but this sort of testing definitely works for testing your applications as well as your algorithms.

ETA: Oh, and thanks for the kind words. :-)

I didn't, but I will and get back to you. There's certainly a need for randomness in unit tests, since I can't be trusted to write tests for the code I wrote (if I knew everything that would break before writing the tests, I'd fix it in the first place).

Not sure if it's directly applicable to Hypothesis, but one way to use QuickCheck for interactive code is to define a type representing actions to take, eg.

  data Action = DoFoo | DoBar | DoSequence [Action] | DoParallel [Action]

We can then write an "run" function which executes these action, and use it in our properties.

It's pretty easy to do this sort of thing in Hypothesis. You can also use [the support for stateful testing directly](http://hypothesis.readthedocs.org/en/latest/stateful.html). I find there's still a place for more granular tests that look more like your classic property based tests with a bit more imperative state floating around though.

I've been using hypothesis for testing a decent sized flask project at work and it's been great.

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