And to be specific, they generally look for _known_ unexpected behavior; in that you need to have a test for it. Though clearly there's still unknowns, like wh

And to be specific, they generally look for _known_ unexpected behavior; in that you need to have a test for it. Though clearly there's still unknowns, like when you're throwing random data at an api to see if you can find bugs. But even still, you know what _ways_ you're doing that. Tests generally won't turn up things nobody has thought to test.