This is why it's important to have tests that assert a system's failure modes too.shouldFitTriangleInTriangleHole()shouldNotFitTriangleInAnyOtherHoles()Bonus points for just parameterizing it.
assert triangleObject.shouldFitInHole(triangleHole) == true assert triangleObject.shouldFitInHole(squareHole) == false
good Tester.
If something stupid can be done, it will be done.