I'm wary of "testing theater" (in the spirit of "security theater"); but I've come to think of testing as similar to two-factor authentication: it doesn't guara

I'm wary of "testing theater" (in the spirit of "security theater"); but I've come to think of testing as similar to two-factor authentication: it doesn't guarantee correctness, but it does reduce the likelihood of bugs and regressions, especially during refactors. I think the other benefit of testability has nothing to do with the tests themselves, but rather the discipline of writing testable code: in general, writing code that is easy to test will tend to be higher-quality and easier to reason about. The thing I'm not fully sold on is mocking, which ends up being a huge timesink, and may or may not improve reliability since you're testing against a fake system and not the real thing. I vastly prefer a combination of small functional/unit tests, and E2E integration tests in a real environment (cypress/etc); the uncanny valley in between has a poor ROI IMO.