A good test is a risky prediction — one the product could plausibly fail. Low-risk tests that pass because there is nothing interesting they could catch are the testing equivalent of unfalsifiable theories, and Popper's demarcation criterion gives us the vocabulary to say so.
Popper and the Risky Test. You've covered modus tollens but stopped short of the inevitable: Popper's demarcation criterion[^1]. A good test is a risky prediction — one the product could plausibly fail. Low-risk tests (tests that pass because there's nothing interesting they could catch) are the testing equivalent of unfalsifiable theories: they look like science but aren't. This would give you a rigorous vocabulary for the intuition behind "my regression suite is green but I don't feel confident."
