2 ms·

I vaguely remember the same advice, it's pretty old. How you use the randomness is test specific, for example in math_add() it'd be something like: jitter =

by Izkata 6mo ago

I vaguely remember the same advice, it's pretty old. How you use the randomness is test specific, for example in math_add() it'd be something like: jitter = random(5) assertEqual(3 + jitter, math_add(1, 2 + jitter)) If it was math_multiply(), then adding the jitter would fail - that would have to be multiplied in. Nowadays I think this would be done with fuzzing/constraint tests, where you define "this relation must hold true" in a more structured way so the framework can choose random values, test more at once, and give better failure messages.

whynotmaybe 6mo ago
> it's pretty old. Damn, must be why only white hair is growing on my head now. >Nowadays I think this would be done with fuzzing/constraint tests, where you define "this relation must hold true" in a more structured way so the framework can choose random values, test more at once, and give better failure messages. So the concept of random is still there but expressed differently ? (= Am I partially right ?)
- Izkata 6mo ago
  Yes, the randomness is still there but less manually specified by the developer. But also I haven't actually used it myself but had seen stuff on it before, so I had the wrong term: it's "property-based testing" you want to look for. Here's an example with a python library: https://hypothesis.readthedocs.io/en/latest/tutorial/introduction.html#testing-a-sorting-algorithm https://hypothesis.readthedocs.io/en/latest/tutorial/introdu... The strategy "st.lists(st.integers())" generates a random list of integers that get passed into the test function. And also this page says by default tests would be run (up to) 100 times: https://hypothesis.readthedocs.io/en/latest/tutorial/settings.html https://hypothesis.readthedocs.io/en/latest/tutorial/setting... So I'm thinking... (not tested) @given(st.integers(), st.integers()) def test_math_add(a, b): assert a + b == math_add(a, b) ...which is of course a little silly, but math_add() is a bit of a silly function anyway.

by Izkata 6mo ago

whynotmaybe 6mo ago

> it's pretty old. Damn, must be why only white hair is growing on my head now. >Nowadays I think this would be done with fuzzing/constraint tests, where you define "this relation must hold true" in a more structured way so the framework can choose random values, test more at once, and give better failure messages. So the concept of random is still there but expressed differently ? (= Am I partially right ?)

Izkata 6mo ago
Yes, the randomness is still there but less manually specified by the developer. But also I haven't actually used it myself but had seen stuff on it before, so I had the wrong term: it's "property-based testing" you want to look for. Here's an example with a python library: https://hypothesis.readthedocs.io/en/latest/tutorial/introduction.html#testing-a-sorting-algorithm https://hypothesis.readthedocs.io/en/latest/tutorial/introdu... The strategy "st.lists(st.integers())" generates a random list of integers that get passed into the test function. And also this page says by default tests would be run (up to) 100 times: https://hypothesis.readthedocs.io/en/latest/tutorial/settings.html https://hypothesis.readthedocs.io/en/latest/tutorial/setting... So I'm thinking... (not tested) @given(st.integers(), st.integers()) def test_math_add(a, b): assert a + b == math_add(a, b) ...which is of course a little silly, but math_add() is a bit of a silly function anyway.