or, maybe, there is something hugely wrong with your code, review pipeline or tests if adding randomness to unit test values makes your tests flaky and this is a good way to find it

or, maybe, it signals insufficient thought about the boundary conditions that should or shouldn't trigger test failures.

doing random things to hopefully get a failure is fine if there's an actual purpose to it, but putting random values all over the place in the hopes it reveals a problem in your CI pipeline or something seems like a real weak reason to do it.