CODEWITHSUNDEEP
pythonpython-hypothesis
Richard
Richard

Reputation: 61289

Make hypothesis test all values

I'm looking for a way to make hypothesis do the following:

@given(device=st.test_every_value_of(["cpu", "gpu"])
def test_a_thing(self, device):
  do_something_with_device(device)

But I haven't found a strategy like st.test_every_value_of.

What's a good way of doing this?

Upvotes: 0

Views: 394

Answers (1)

Richard
Richard

Reputation: 61289

It turns out there are two potential solutions.

The first is to use st.sampled_from:

@given(device=st.sampled_from(["cpu", "gpu"]))
def test_a_thing(self, device):
  do_something_with_device(device)

st.sampled_from is not guaranteed to test all the values passed to it. However, Hypothesis, by default, generates 100 test cases from the specified strategies. If st.sampled_from contains >100 items or if it's used in conjunction with other strategies then it may not test all values; however, for smaller tests it may work fine.

The better solution is probably to use pytest's parameterize:

import pytest

@pytest.mark.parameterize("device", ["cpu", "gpu"])
def test_a_thing(self, device):
  do_something_with_device(device)

If this is used in conjunction with hypothesis then hypothesis will run 100 tests for each instance generated by parameterize.

Upvotes: 1

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